摘要:

The immunosuppressive activities of a newly discovered macrolide extracted fromStreptomyces tsukubaensis, FK506, were examined using 38 renal allografts in the beagle dog. The median survival time was 15.5 days in dogs without treatment, 61 days with a dose of 0.08 mg/kg/day and 176 days with a dose of 0.16 mg/kg/day of intramuscularly administered FK506. Prolongation of survival was statistically significant when compared with controls (P= 0.02, 0.0044, respectively). None of 6 recipient dogs receiving the agent at a dose of 0.16 mg/kg/day encountered rejection during the treatment course. Three of them survived over 200 days. Oral administration of FK506 at a dose of 0.32 mg/kg/day did not prolong the median survival time (20.5 days) compared with the placebo treated control (16.5 days), but oral treatment with 1.0 mg/kg/day resulted in all of the recipient dogs surviving over 130 days. Histological studies of 7 kidney graft biopsy specimens of the dogs surviving over 3 months revealed no cell infiltration or only some degree of reversible interstitial cell infiltration, but vascular and glomerular changes were not observed in any of the specimens. Irregularity of nuclear shape and cytoplasmic vacuolation of the pars recta of the proximal tubules were observed in one dog each. Liver biopsy specimens showed no consistent evidence of hepatocellular damage. Three dogs died of intussusception 2–3 weeks posttransplant. The dogs treated intramuscularly with 0.32 mg/kg/day suffered from anorexia. Two dogs receiving oral treatment at a dose of 1.0 mg/kg developed papilloma of the skin around day 60, but the tumors disappeared by day 120. We conclude that FK506 is a powerful immunosuppressant in the dog with tolerable side effects.

ISSN:0041-1337    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Immunosuppressive activities of the newly discovered FK506, isolated fromStreptomyces tsukubaensis, were examined by using cardiac allotransplantation in the rat, and the mechanisms underlying induction and maintenance of FK506-induced long-term allograft survival were studied. Male rats of WKA (RT1k) and F344 (RT1Iv1) strains were used as recipients and donors, respectively, and those of BN (RT1n) strain were used as third-party donors. Treatment with FK506, beginning from the day of allografting for 14, 10, or as few as 4 days, prolonged allograft survival significantly across the major histocompatibility barrier. The minimum doses for prolonging graft survival were 0.1 mg/kg/day by intramuscular treatment and 1.0 mg/kg/day by oral treatment. Treatment with FK506 at a dose of 0.32 mg/kg/day from day 4 until day 10 resulted in all the grafts surviving indefinitely and from days 5 to 10, half the grafts survived indefinitely, suggesting that the agent inhibited ongoing rejection. On the other hand, cyclosporine treatment at a dose of 20 mg/kg/day from day 2 did not prolong graft survival time statistically significantly.Induction of prolonged graft survival was not obtained by pretreatment of the prospective donor or recipient; prolonging effects were observed only when the agent was administered after allografting. Thus, the primary effect of the agent is exerted on responder lymphocytes reacting to the donor antigens in the induction phase of long-term graft acceptance.The mechanisms underlying the maintenance of long-term grafts were analyzed by testing the capacity of lymphocytes or serum of long-term graft-bearing rats to inhibit graft rejection in irradiated grafted hosts. Transfer of 2×108lymphocytes from FK506-induced long-term F344 graft-bearing WKA rats resulted in indefinite survival of F344 heart allografts, but it did not prolong survival of third-party BN hearts. Transfer of 2.5 ml serum from long-term graft-bearing rats also prolonged graft survival of F344 hearts, but not BN hearts. These results suggest that donor strain–specific suppressor cells and humoral factor(s) are induced by treatment with FK506 in the presence of allografts, and that they play at least partial roles in the maintenance of long-term allograft acceptance.

ISSN:0041-1337    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Cultured neonatal rat islets were transplanted across six strain combinations into nonimmunosuppressed allogeneic recipients. Islets were isolated nonenzymatically by an in vitro method and were cultured at 37°C in 5% CO2in air for 10 days prior to transplant. Transplants to nondiabetic recipients across four allogeneic barriers resulted in morphologically intact and wellgranulated islet tissue present at the graft site in 54 of 55 cases for periods lasting as long as 445 days (mean day of sacrifice was 163). In trials using diabetic recipients, ACIs receiving WF islets (n = 3) and outbred Holtzmans receiving Holtzman islets (n = 3) were reversed and did not return to the hyperglycemic state for experimental periods of up to 430 days.

ISSN:0041-1337    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Requirements for sustained engraftment of fetal liver hematopoietic stem cells were evaluated in 45 dogs. Pretransplant preparative treatment with total-body irradiation, 14.7 Gy, permitted engraftment of DLA-compatible fetal liver cells. Radiation alone was inadequate in DLA-haploidentical or DLA-mismatched transplants; none of 5 dogs had engraftment. Addition of cyclosporine facilitated engraftment. The combination of 14.7 or 16.1 Gy total-body irradiation (TBI) and cyclosporine allowed engraftment in 15 of 19 (78%) dogs receiving DLA-histoincompatible grafts and 11 Gy TBI plus cyclosporine allowed engraftment in 4 of 10 dogs. Restoration of granulopoiesis and thrombopoiesis was rapid; recovery of lymphocytes was relatively delayed, especially in recipients of incompatible fetal liver cells. Cumulative one-year survival was decreased in recipients of incompatible grafts due to early posttransplant infections. These data suggest that fetal liver transplantation is a potential approach in patients who lack an HLA-identical donor for bone marrow transplantation.

ISSN:0041-1337    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

The critical histologic review of our experience with small bowel allotransplantation in the dog is presented. While “classical” rejection with dense small cell infiltration and mucosal destruction does occur, more common is the “atypical” rejection reaction in which cellular infiltration is sparse. This “atypical” rejection was characterized by a significant decrease of mucosal epithelial structures with increased mitotic figures in crypt cells and frequent vascular changes, including segmental fibrinoid necrosis and thrombosis with or without overlying mucosal destruction. Substantial regenerating capacity of bowel mucosa tends to compensate for the destruction, complicating the histology. The host lymph nodes and spleen present a histologic picture highly suggestive of GVH reaction. The reduction in host lymphocytes in these organs from karyorrhexis with replacement by histiocytes and subsequently by plasma cells is described. It is emphasized that rejection and GVH are not mutually exclusive and occur simultaneously. The decrease of functional mucosal mass could well account for the nutritional malsequelae. Also, the weakening of immune structures on the host and the graft side may predispose to catastrophic enterogenous infections, perhaps explaining the large number of animals that die without overt signs of rejection following small bowel transplantation.

ISSN:0041-1337    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

We have examined the role of entire major histocompatibility complex (MHC) disparity, individual class II or class I alloantigens in the rejection of vascularized heart allografts. Our results demonstrate that entire MHC, as well as both class II and class I disparities, may induce acute heart graft rejection or severe and irreversible heart muscle destruction.However, in 1 of 2 combinations differing at class II and 1 of 5 differing at class I, hearts have shown a good function > 100 days postgrafting. Furthermore, each donor-recipient combination has demonstrated a unique pattern of heart allograft function as well as a degree of heart muscle damage. In conclusion, these data suggest that the rejection process depends upon multiple factors such as the immune-response-gene-regulated immuno-responsiveness of the recipient as well as the expression of alloantigens on heart grafts during the induction and effector phases of the immune response.

ISSN:0041-1337    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

The immunosuppressive effect of splenectomy, alone or in combination with cyclosporine (CsA), was examined in hamster-to-rat orthotopic liver xenografts. The mean survival time was 7.3±0.5 days in untreated controls, 7.6±0.8 days with 40 mg/kg/day CsA, 7.2±0.4 days with splenectomy alone, and 17.6±5.6 days with splenectomy combined with 30 mg/kg/day CsA (P< 0.01). The longest survival time was 27 days in this group. Marked enlargement of the spleen and high lymphocytotoxic antibody titer were characteristic of the unmodified recipients and those treated with CsA alone. Splenectomy by itself decreased the antibody formation without improvement of graft survival. In animals treated with the combined regimen, the lymphocytotoxic antibody titer was significantly suppressed, and the PMN and round cell infiltration were greatly reduced. Therefore, a synergistic effect was postulated between cyclosporine and splenectomy in this liver xenograft system.

ISSN:0041-1337    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

A series of 25 different ricin A-chain immunotoxins (IT) were prepared with monoclonal antibodies reacting with several T cell antigens belonging to different clusters of differentiation (CD) to select the most appropriate immunotoxins (IT) for mature T cell depletion. Our screening procedure was performed in 2 steps. First, IT were evaluated using protein synthesis inhibition assay on clonogenic malignant cells in order to determine the most active IT for a given CD. Second, IT thus selected were evaluated for both mature T cell killing efficacy and tolerance on hematopoietic progenitor cells (HPC). This study showed that (1) different IT directed against the same CD antigen displayed a wide range of activity, suggesting the need for a large screening of IT to determine the most appropriate antibody for a given target antigen; (2) anti-CD3 and anti-CD5 ricin A-chain IT are the most active, displaying a cytoreduction of more than 2 logs on mature T cells; (3) the 3 different anti-CD2 ricin A-chain IT evaluated in this study induced poor mature T cell cytoreduction despite their relative efficacy on leukemic cells; (4) anti-CD8 ricin A-chain IT showed almost no efficacy on relevant target cells; (5) no toxicity on HPC was found for concentrations up to 10−8M of A-chain whatever the IT used.

ISSN:0041-1337    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Daunomycin coupled via an acid-sensitive spacer to monoclonal Thy-1.2-specific antibody was used to purge T lymphocytes from a 1:1 mixture of murine C57BL/6J bone marrow and spleen cells prior to engraftment in fully allogeneic, irradiated BALB/c recipients. Treatment of bone marrow with the immunotoxin at a concentration used for purging had no effect on the viability of committed hematopoietic progenitor or multipotent stem cells. All of the recipients of purged bone marrow were at least 80% chimeric for donor peripheral blood cells and none developed graft-versus-host disease. Out of 50 chimeras, 49 were still alive more than 200 days posttransplantation. The chimeras were shown to be tolerant to donor tissue as tested by mixed lymphocyte reactivity, cell-mediated cytotoxicity, and skin grafting. The same tests revealed full immunocompetence of chimeras to third-party alloantigens. In vivo IgM and IgG antibody responses to sheep red blood cells were similar in magnitude in allogeneically and syngeneically reconstituted mice.

ISSN:0041-1337    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

The incidence of arterial and venous thromboembolic complications was compared in 224 renal allograft recipients who were prospectively randomized and stratified by risk to treatment with either cyclosporine-prednisone (CsA-P) (n=117) or azathioprine-prednisone-antilymphocyte globulin (AZA-P-ALG) (n=107). Thirteen CsA patients (11%) had 22 thromboembolic events, while 19 AZA patients (18%) had 24 events (P= 0.22). There was no significant difference between the 2 regimens in the number of patients with each type of venous or arterial event or in the number of patients with multiple or lethal events. The incidence of “minor” complications (all except myocardial infarction and stroke) in the related donor subgroup (n=85) and the overall incidence of thromboembolism in the diabetic subgroup (n=125) were both significantly higher in AZA-treated patients (P= 0.008 and 0.045, respectively). Thus, CsA immunosuppression does not appear to be a risk factor for thromboembolic disease, and it may in fact lower the incidence of thromboembolism in diabetic renal allograft recipients.

ISSN:0041-1337    

出版商:OVID    

年代:1987

数据来源: OVID