OBJECTIVETo study the methods and mechanisms of immune tolerance in cardiac transplantation.

METHODSMale DA rat hearts were transplanted to male Lewis rats using Ono's model and randomly divided into five groups: untreated, intravenous injection of 1 x 10(8) DA splenocytes to Lewis rat, intraperitoneal injection of cyclophosphamide (100 mg/kg) to Lewis rat, intravenous injection of 1 x 10(8) DA splenocytes combined with intraperitoneal injection of cyclophosphamide (100 mg/kg) to Lewis rat, multiple injection of DA rat splenocytes with intraperitoneal injection of cyclophosphamide, 11 days later heart transplantation was performed. Mean survival time (MST), histological changes, mixed lymphocyte reaction (MLR), the role of interleukin-2 (IL-2) to MLR and the role of tolerant rat splenocytes to MLR were measured after operation.

RESULTSThe survival time of heart allografts in the group of multiple injection of DA rat splenocytes with intraperitoneal injection of cyclophosphamide [MST: (85.3 +/- 7.5) d, t = 0, P < 0.01] was significantly longer than in the groups of untreated [MST: (7.3 +/- 1.0) d], intravenous injection of 1 x 10(8) DA splenocytes to Lewis rat [MST: (7.9 +/- 0.9) d], intraperitoneal injection of cyclophosphamide (100 mg/kg) to Lewis rat [MST: (8.1 +/- 1.2) d], intravenous injection of 1 x 10(8) DA splenocytes combined with intraperitoneal injection of cyclophosphamide (100 mg/kg) to Lewis rat [MST: (25.8 +/- 3.5) d]. Only a few inflammatory cells infiltrated in cardiac allografts in the group of multiple injection of DA rat splenocytes with intraperitoneal injection of cyclophosphamide. MLR in the group of multiple injection of DA rat splenocytes with intraperitoneal injection of cyclophosphamide were significantly decreased compared with those of normal control (t = 0, P < 0.01). IL-2 could partly reversed the hyporesponsiveness of MLR in tolerant rats, the tolerance could be transferred in vitro.

CONCLUSIONSMultiple injection of donor splenocytes combined with intraperitoneal injection of cyclophosphamide to recipients could induce immune tolerance to cardiac allografts.

Adoptive Transfer ; Animals ; Cell Transplantation ; Cyclophosphamide ; pharmacology ; Graft Enhancement, Immunologic ; methods ; Graft Survival ; Heart Transplantation ; immunology ; Injections, Intravenous ; Isoantigens ; administration & dosage ; immunology ; Male ; Rats ; Rats, Inbred BN ; Rats, Inbred Lew ; Rats, Inbred Strains ; Rats, Wistar ; Spleen ; cytology ; Transplantation Tolerance ; drug effects ; Transplantation, Heterologous ; immunology

OBJECTIVETo investigate the feasibility of strategy of allograft tolerance induction by injection of FasL-decorated donor splenocytes.

METHODSChimeric FasL with core streptavidin (SA-FasL) was efficiently displayed on the surface of splenocytes by the technology of ProtEx™. Heterotopic heart transplant procedures were performed from donor WF rats to recipient ACI rats, F344 rats were used as third-party. Intraperitoneal injection of ACI rats with "decorated" WF splenocytes was used as the approach to induce tolerance in this study. According to different therapeutic strategies, three groups were set up: SA-FasL group (n = 23), SA group (n = 20) and naive splenocytes only group (n = 8). No treatment group was regarded as control (n = 10). Adoptive transfer was underwent with injection of splenocytes from tolerant recipients into naive ACI followed by heart transplant procedures. Mixed lymphocyte reaction (MLR) and third party transplantation were performed to detect allogenic tolerance.

RESULTSThe injection of ACI rats with WF rat splenocytes displaying SA-FasL on their surface resulted in tolerance to donor, but not F344 third-party cardiac allografts. There were 70% cardiac allografts in SA-FasL group achieved long term survival, and it was significantly higher than the rats in other groups (P < 0.05). Adoptive transfer of splenocytes from long-term graft recipients into naive unmanipulated ACI rats resulted in indefinite survival of secondary WF grafts. Donor specific tolerance was identified by MLR and third-party transplant.

CONCLUSIONThe direct display of SA-FasL on the cell membrane in a rapid and efficient manner provides a practical and clinically applicable means of immunomodulation for tolerance induction with considerable therapeutic potential for transplantation.

Animals ; Fas Ligand Protein ; genetics ; immunology ; Heart Transplantation ; immunology ; Male ; Rats ; Rats, Inbred ACI ; Rats, Inbred F344 ; Rats, Inbred WF ; Spleen ; cytology ; metabolism ; Tissue Donors ; Transplantation Tolerance ; immunology

To establish a murine carotid artery transplantation model for the study of the chronic rejection, 80 rats were divided into two groups, an allotransplant (ACI-Lewis) group and an isotransplant (Lewis-Lewis) group (control group). The donor carotid artery and the recipient carotid artery were anastomosed by using a polyethylene cuff (internal diameter: 0.7 mm, length: 3 mm).The pathological changes of carotid artery transplant were observed 14, 28 and 56 days after the transplantation. The results showed that the model was successfully established in 95% of the animals. The chronic rejection-associated arteriosclerosis was induced 28 days after the transplantation. The new chronic rejection model of carotid artery by using cuff technique caused fewer traumas and was easy to make. The pathological changes of the transplant mimicked the chronic rejection-associated arteriosclerosis found in human transplant.
Anastomosis, Surgical/methods ; Arteriosclerosis ; Carotid Artery, Common/*transplantation ; Delayed Graft Function ; Graft Rejection/*pathology ; Models, Animal ; Polyethylene ; Rats, Inbred ACI ; Rats, Inbred Lew

OBJECTIVETo study the role of T suppressor cells in immune tolerance to cardiac allografts in the rats.

METHODSMale DA rat hearts were transplanted to male Lewis rats using Ono's model and randomly divided into five groups: group 1: untreated, group 2: portal venous injection of 3 x 10(8) DA splenocytes to Lewis rat, group 3: intraperitoneal injection of cyclophosphamide (80 mg/kg) to Lewis rat, group 4: portal venous injection of 3 x 10(8) DA splenocytes combined with intraperitoneal injection of cyclophosphamide (80 mg/kg) to Lewis rat, 15 days later heart transplantation was performed. Group 5: intravenous injection 3 (108 splenocytes of group 4 to normal recipient, and then heart transplantation was performed. Mean survival time (MST), histological changes, mixed lymphocyte reaction (MLR) were measured after operation.

RESULTSThe survival time of heart allografts in the group 4 [MST: (71.5 +/- 29.1) d, t = -14.063, -13.915, -13.777; P < 0.01] was significantly longer than in the groups of 1 [MST: (7.3 +/- 1.0) d], 2 [MST: (7.8 +/- 0.8) d], 3 [MST: (8.2 +/- 1.1) d ]. Only a few inflammatory cells infiltrated in cardiac allografts in the groups of 4 and 5. MLR in the groups of 4 and 5 were significantly decreased compared with those of normal control (t = 29.902, 23.047; P < 0.01).

CONCLUSIONSPortal venous injection of donor splenocytes combined with intraperitoneal injection of cyclophosphamide could induce immune tolerance to cardiac allografts. The immune tolerance could be transferred through splenocytes. T suppressor cells play an important role in the immune tolerance.

Animals ; Cyclophosphamide ; therapeutic use ; Graft Enhancement, Immunologic ; methods ; Heart Transplantation ; immunology ; Immunosuppressive Agents ; therapeutic use ; Injections, Intraperitoneal ; Lymphocyte Transfusion ; methods ; Male ; Random Allocation ; Rats ; Rats, Inbred Lew ; Rats, Inbred Strains ; T-Lymphocytes, Regulatory ; immunology ; Transplantation Tolerance ; immunology ; Transplantation, Homologous ; immunology

The pathogenesis of diabetic retinopathy has not been fully explained. The earliest histological lesion is the loss of intramural pericytes and thickening of the basement membrane. Increased activity of the polyol pathway is a probable mechanism for these two abnormalities. Investigations have suffered from the lack of an exact animal model simulating the human condition. Examination of the retina in the spontaneously diabetic SHR/N:Mcc-cp rat demonstrated degeneration and loss of intramural pericytes, a progressive increase in basement membrane thickness, and microinfarctions with an area of non-perfusion. Therefore, this model may be used to clarify the biochemical mechanisms linking the metabolic abnormalities of diabetes and retinopathy.
Animal ; Diabetic Retinopathy/pathology* ; Disease Models, Animal ; Female ; Hybridization ; Male ; Rats ; Rats, Inbred SHR/genetics ; Rats, Inbred Strains/genetics ; Retina/pathology* ; Retinal Degeneration/pathology

OBJECTIVETo study the inhibitory effect of Juhua Jueming powder (JJP) on high-risk corneal transplantation immune rejection in rats.

METHODSThe high-risk corneal transplantation immune rejection rat model was established by inducing corneal neoangiogenesis by suture method and the penetrating transplantation. Model rats were divided into two groups, the treated group and the control group, they were administered with JJP 0.1 g (dissolved in 2 mL water) and normal saline respectively via gastric infusion every day after transplantation. The survival status of the allograft, histopathology, local and systemic immune status in the recipients were observed using immunofluorescence histochemistry and flow cytometry.

RESULTSThe survival time of the allograft in the treated group (14.50 +/- 3.55 days) was significantly longer than that in the control group (8.25 +/- 0.71 days, P < 0.01). Levels of Fas, FasL expressions in iris were stronger, and the percentage of CD4 CD FOXP3 positive cells in peripheral blood was less (5.11 +/- 3. 92% vs. 14.81 +/- 2.58%) in the control group than those in the treated group respectively. The concentration of IL-2 was lower while that of IL-10 was higher in aqueous humor of the treated group than those of the control group, respectively.

CONCLUSIONJJP has certain effect for preventing high-risk corneal transplantation immune rejection in rat model.

Animals ; Corneal Transplantation ; adverse effects ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Graft Rejection ; prevention & control ; Phytotherapy ; Rats ; Rats, Inbred F344 ; Rats, Inbred Lew

OBJECTIVETo investigate the role of intrahepatic CD4(+)CD25(+) T regulatory cells and Foxp3 gene in the natural tolerance in rat liver transplantation.

METHODSThe orthotopic liver transplantation models of inbred rats (LEW and DA rats) were established with double-sleeve technique and the models were divided into two groups: tolerance group (TOL group, LEW-to-DA) and rejection group (REJ group, DA-to-LEW). The intrahepatic lymphocytes from each group were isolated by using density gradient centrifugation. CD4(+)CD25(+) T cells were isolated by magic cell sorting system (MACS) and identified by flow cytometry (FCM). CD4(+)CD25(+) Tr cells suppression on the proliferation of CD4(+)CD25(-) T effector cells were analyzed by cell proliferation assay in vitro. Western blot was used to detect Scurfin protein expression of CD4(+)CD25(+) Tr cells.

RESULTSCD4(+)CD25(+) Tr cells developed significantly greater in the TOL group than in the REJ group. In vitro, the spleen cells from LEW rats can irritate the proliferation of CD4(+)CD25(+) T cells more obviously than the syngeneic spleen cells. CD4(+)CD25(+) T cells could suppress the proliferation of CD4(+)CD25(-) T cells, but the inhibition was reversed by exogenous IL-2 (200 U/ml).

CONCLUSIONSThe immune suppression function of CD4(+)CD25(+) Tr cell, mediated by Foxp3 gene, is one of the mechanisms in liver transplantation tolerance.

Animals ; Blotting, Western ; CD4-Positive T-Lymphocytes ; cytology ; immunology ; metabolism ; Cells, Cultured ; Flow Cytometry ; Forkhead Transcription Factors ; metabolism ; Graft Rejection ; immunology ; Interleukin-2 Receptor alpha Subunit ; immunology ; Liver Transplantation ; immunology ; Male ; Models, Animal ; Rats ; Rats, Inbred Lew ; Rats, Inbred Strains ; Transplantation Tolerance ; immunology

An orthotopic penetrating keratoplasty model was developed in the rat. An oversized (0.5 mm) graft was used and 8 interrupted sutures were applied. These sutures were not removed. Eleven grafts out of 13 were rejected by the 3rd week in the disparate group (Brown Norway rat to Lewis rat transplantation group), which was characterized by edema, opacity, and neovascularization. All grafts remained clear in the syngeneic group (Lewis rat to Lewis rat transplantation group). Immunohistochemical examination was performed. This model seems to be a reliable and reproducible one to evaluate rejection reaction in corneal transplantation.
Animals ; Female ; Graft Rejection ; Keratoplasty, Penetrating/immunology/*methods/pathology ; Lymphocyte Subsets/immunology/pathology ; Macrophages/immunology/pathology ; Rats ; Rats, Inbred BN ; Rats, Inbred Lew ; Transplantation, Homologous ; Transplantation, Isogeneic

OBJECTIVETo investigate the mechanism underlying the inhibitory effect of tacrolimus (FK506) against acute liver graft rejection.

METHODSRat models of orthotopic liver transplantation were divided into 3 groups, namely the tolerance group with Brown Norway (BN) rats as the donors and Lewis rats as the recipients, rejection group with Lewis rats as donors and BN rats as recipients, and FK506 group with the same donor-recipient pair as in the rejection group and FK506 treatment. The recipients were sacrificed 7 days after the transplantation, and the hepatic histology, cytokine levels, and glucocorticoid-induced tumor necrosis factor-related protein ligand (GITRL) expression in the liver and Kupffer cells were observed and detected.

RESULTSCompared with the tolerance group, the rejection group showed increased GITRL expressions in the liver and Kupffer cells (P<0.05), which was significantly lowered by FK506 treatment (P<0.05). Acute liver graft rejection caused significantly elevated interferon-γ (IFN-γ) levels and decreased interleukin-10 (IL-10) levels in the plasma and Kupffer cells (P<0.05), and these changes were obviously attenuated by FK506 treatment (P<0.05).

CONCLUSIONThe effect of FK506 in suppressing acute liver graft rejection is probably associated with down-regulated GITRL expression in the liver and Kupffer cells.

Animals ; Carrier Proteins ; metabolism ; Graft Rejection ; prevention & control ; Kupffer Cells ; metabolism ; Liver ; metabolism ; Liver Transplantation ; Male ; Rats ; Rats, Inbred BN ; Rats, Inbred Lew ; Tacrolimus ; pharmacology

OBJECTIVETo evaluate the effect of HSGJ on chronic allograft nephropathy (CAN) using standard rat model of CAN.

METHODRenal transplantation was performed with Fisher rats as donors and Lewis rats as recipients. All the recipients were randomly divided into control group and medication groups (high and low dosage of HSGJ, fed every other day). After 16 weeks of treatment, renal function and the histological alteration of CAN were measured. The expression of the TGFbeta1 mRNA in the allograft was evaluated by real-time PCR.

RESULTThe content of 24 h urine protein and the level of serum creatinine in the medication groups were significantly decreased (P < 0.01) as compared with control group, whereas the creatinine clearance was increased (P < 0.01). The degree of glomerular sclerosis and the Banff score of medication groups were lower than the control group respectively (P < 0.01), in consistent with decreased expression of the TGF 1mRNA.

CONCLUSIONHSGJ can prevent the chronic allograft nephropathy and the mechanism may be related with its influence on the expression of the TGFbeta1.

Animals ; Chronic Disease ; Drugs, Chinese Herbal ; therapeutic use ; Glomerulonephritis ; etiology ; immunology ; prevention & control ; Graft Rejection ; drug therapy ; Immunosuppressive Agents ; therapeutic use ; Kidney Transplantation ; adverse effects ; Random Allocation ; Rats ; Rats, Inbred F344 ; Rats, Inbred Lew ; Transplantation, Homologous