Transplantation of CD95 ligand-expressing grafts: influence of transplantation site and difficulty in protecting allo- and xenografts

BACKGROUND

CD95 and its ligand (CD95L) have been implicated in the regulation of immune responses. Recently, it was reported that CD95L expression prevented rejection of allogeneic grafts transplanted under the kidney capsule. In contrast, we reported that enforced CD95L expression in subcutaneously grafted cells induced acute rejection even in the syngeneic or immunodeficient hosts. In this study, we investigated whether the CD95L-expressing cells could be protected from rejection when transplanted under the kidney capsule.

METHODS

CD95-negative cells (baby hamster kidney and L5178Y lymphoma cells) were transfected with CD95L cDNA to express functional CD95L. The cells were transplanted into skin or renal subcapsular space of immunocompetent or T cell-deficient nu/nu mice.

RESULTS

The parental cells grew well in nu/nu or syngeneic mice but were rejected in allogeneic or xenogeneic immunocompetent mice. The CD95L transfectants were rejected when transplanted subcutaneously in all types of mice studied. However, when transplanted under the kidney capsule, they survived in nu/nu or syngeneic mice but were rejected in allogeneic or xenogeneic immunocompetent mice.

CONCLUSIONS

These results imply that CD95L expression may not be sufficient to protect the grafts from rejection, and the survival of CD95L-bearing grafts is substantially influenced by the site of transplantation.

Contribution of Fas ligand to T cell-mediated hepatic injury in mice

BACKGROUND & AIMS

Fas has been implicated in liver damage. The aim of this study was to investigate the role of its ligand to induce hepatocyte death and liver damage in T cell-dependent hepatitis.

METHODS

Fas ligand-mediated lysis of primary hepatocytes from C57BL/6 wild-type, Fas ligand-deficient gld, and Fas-deficient lpr mice and concanavalin A-induced hepatitis in these mice were assessed.

RESULTS

Freshly isolated hepatocytes from wild-type or gld mice, but not those from lpr mice, were susceptible to Fas ligand-mediated lysis. When concanavalin A was intravenously administered into wild-type mice, they developed acute hepatic injury with massive degenerative changes in hepatocytes. In contrast, both gld and lpr mice had lower aminotransferase levels with milder histological changes. Reverse-transcription polymerase chain reaction and flow cytometric analysis showed that Fas ligand was induced in the liver shortly after the concanavalin A injection and was predominantly expressed on intrahepatic T cells. Administration of monoclonal antibody neutralizing mouse Fas ligand could reduce the aminotransferase increase.

CONCLUSIONS

The results indicate that Fas ligand plays a role in the T cell-dependent hepatitis induced by concanavalin A administration.

Immunoregulation via adhesion molecules in allogenic and xenogenic hepatocyte transplantation to Nagase's analbuminemic rats

We investigated the effects of monoclonal antibodies (mAbs) against lymphocyte function-associated antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1) on intrasplenic allogenic and xenogenic hepatocyte transplantation (HCTx) to analbuminemic rats. Ten to 12-wk-old male Nagase's analbuminemic rats (RT1l) were used as recipients, Wistar/Shi rats (RT1k) were used as donors for allografts and BALB/C mice were used as donors for xenografts. The experimental groups were as follows: group 1, allo-HCTx (n = 7); group 2, allo-HCTx + antirat ICAM-1/antirat LFA-1 mAbs (1.0 mg/kg/day, for 7 days, respectively) (n = 6); group 3, xeno-HCTx (n = 5); group 4, xeno-HCTx + mAbs (antimouse LFA-1/antirat ICAM-1) (n = 5). group 5, xeno-HCTx + mAbs (antirat LFA-1/antimouse ICAM-1) (n = 5). Serum rat albumin levels were measured in groups 1 and 2, and serum mouse albumin levels were measured in groups 3, 4, and 5, as indicators of the function of grafted hepatocytes. In allotransplantation groups, the serum rat albumin levels in the mAbs-treated group were significantly higher than those in the control group for 6 wk after transplantation. In xenotransplantation groups, no increase in the serum mouse albumin levels was detected in any group

Immunoregulation via Adhesion Molecules in Allogenic and Xenogenic Hepatocyte Transplantation to Nagase's Analbuminemic Rats

We investigated the effects of monoclonal antibodies (mAbs) against lymphocyte function-associated antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1) on intrasplenic allogenic and xenogenic hepatocyte transplantation (HCTx) to analbuminemic rats. Ten to 12-wk-old male Nagase's analbuminemic rats (RT1l) were used as recipients, Wistar/Shi rats (RTlk) were used as donors for allografts and BALB/C mice were used as donors for xenografts. The experimental groups were as follows: group 1, allo-HCTx (n = 7); group 2, allo-HCTx + antirat ICAM-1/antirat LFA-1 mAbs (1.0 mg/kg/day, for 7 days, respectively) (n = 6); group 3, xeno-HCTx (n = 5); group 4, xeno-HCTx + mAbs (antimouse LFA-1/antirat ICAM-1) (n = 5). group 5, xeno-HCTx + mAbs (antirat LFA-1/antimouse ICAM-1) (n = 5). Serum rat albumin levels were measured in groups 1 and 2, and serum mouse albumin levels were measured in groups 3, 4, and 5, as indicators of the function of grafted hepatocytes. In allotransplantation groups, the serum rat albumin levels in the mAbs-treated group were significantly higher than those in the control group for 6 wk after transplantation. In xenotransplantation groups, no increase in the serum mouse albumin levels was detected in any group.

[A case of unresectable pancreatic cancer successfully treated with continuous venous daily infusion of 5-FU and low-dose CDDP]

This case was a 61-year-old male diagnosed with pancreatic cancer who had a celiotomy. The tumor invasion involved the pancreas body and head. Ultrasonograph examination revealed that all the celiac artery, supramesenteric artery, and portal vein were occluded in the tumor. Because of the unresectability of the tumor, a palliative operation was carried out, and during the following 9 months he was given UFT 300 mg daily. Because abdominal ascites accompanied the tumor growth, the patient underwent combination chemotherapy of cisplatin 5 mg/day x 5/week and continuous infusion of 5-fluorouracil 250 mg/day for 4 weeks. Remarkable reduction of the abdominal ascites and decline of the tumor markers (CEA, CA19-9) was observed in the course of the chemotherapy. Bone marrow function was suppressed by the agents, but granulocyte colony stimulating factor (G-CSF) was very effective for recovery from the damage. Two months after discharge, abdominal ascites recurred. The patient received the same serial chemotherapy for 6 weeks, and now is followed as an outpatient.

Antitumor effect of locally produced CD95 ligand

Activation of the cell-surface antigen CD95 induces apoptosis of CD95-bearing tumor cells. In this study, we investigated the antitumor effect of locally produced CD95 ligand (CD95L) on CD95-negative tumor cells in vivo. Introduction of CD95L cDNA into murine tumor cells did not affect growth in vitro but caused rejection in vivo. Neutrophils were primarily responsible for this rejection. A CD8 T cell-mediated protective immunity against subsequent challenge with parental tumor cells was also elicited. These results provide evidence for the potential utility of CD95L in tumor eradication and also reveal a proinflammatory function of CD95L.

Lack of cognate help by CD4+ T cells and anergy of CD8+ T cells are the principal mechanisms for anti-leukocyte function-associated antigen-1/intercellular adhesion molecule-1-induced cardiac allograft tolerance

Combined treatment with anti-leukocyte function-associated antigen-1 (LFA-1) and anti-intercellular adhesion molecule-1 (ICAM-1) monoclonal antibodies leads to allograft tolerance in murine cardiac transplantation. In the present study, we analyzed the mechanisms for this tolerance induction. In the tolerant mice, proliferative response of splenic T cells against donor-type cardiac myocytes and of CD8+ T cells against donor-type alloantigens was impaired as compared with responses in naive or rejected mice, but was completely restored with exogenous interleukin 2. This suggests that class I-restricted CD8+ T cells of tolerant mice were rendered anergic against donor-type alloantigens in the periphery. In contrast, proliferative response of CD4+ T cells against donor-type alloantigens in vitro was comparable between tolerant and naive mice. When heart and skin grafts from the same donor (BALB/c [H2d]) were simultaneously transplanted to C3H mice (H2k), both were rejected within 29 days, even though the mice were similarly treated with anti-LFA-1 and anti-ICAM-1 monoclonal antibodies. In contrast, when heart graft from BALB/c and skin graft from third-party donor (C57BL/6 [H2b]) were simultaneously transplanted to C3H mice under the same condition, the heart graft was accepted indefinitely and the skin graft was rejected. These findings suggest that the peripheral tolerance against cardiac allografts could be induced by selective inactivation of alloreactive CD8+ T cells resulting from the lack of cognate help by CD4+ T cells.

Contribution of Fas ligand to cardiac allograft rejection

Effector mechanisms for allograft injury remain unclear. In the present study, we verified the contribution of Fas and Fas ligand (FasL) to cardiac allograft rejection by utilizing the Fas-deficient lpr or FasL-deficient gld mice as the donor or recipient. Cardiac myocytes prepared from normal mice, but not those from lpr mice, constitutively expressed Fas and were susceptible to FasL-mediated lysis. Survival of cardiac allografts was substantially prolonged when gld or lpr mice were used as the recipient. In contrast, cardiac allografts from lpr mice were normally rejected without a delay. Histological examination of the grafts in the gld or lpr recipients demonstrated a lesser cellular infiltration and much milder myocyte damage. Proliferative response and cytotoxic T lymphocyte induction against the donor-type alloantigens were not impaired in the gld or lpr recipients. These results indicate a substantial contribution of FasL to cardiac allograft rejection, independent of Fas in the grafts. This ralses a possibility that FasL may be more generally involved in tissue damage associated with various diseases than expected from the expression of Fas in the target organs.

CD86 (B70/B7-2) on endothelial cells co-stimulates allogeneic CD4+ T cells

In vascularized organ transplantation, vascular endothelial cells (EC) confronting recipient T cells are potentially significant APC initiating cellular immune responses that lead to rejection. In the present study, we studied the ability of human EC to stimulate allogeneic T cells and the co-stimulatory molecules involved in this response. On both human umbilical vein endothelial cells (HUVEC) and microvascular endothelial cells (MVEC), MHC class I, intercellular adhesion molecule (ICAM)-1 and CD86 were constitutively expressed as assessed by flow cytometry. After IFN-gamma treatment, MHC class II expression was induced, and MHC class I and ICAM-1 were up-regulated. In contrast, the expression of CD86 was unchanged and CD80 was undetectable even after IFN-gamma treatment. Highly purified CD4+ T cells proliferated in response to IFN-gamma-treated allogeneic HUVEC and MVEC, and this response was efficiently blocked by mAb to MHC class II, ICAM-1 and CD86. Furthermore, the addition of anti-CD86 mAb to the primary culture with allogeneic EC resulted in the induction of alloantigen-specific anergy. These results suggest that CD86 expressed on EC plays a critical role in initiating cellular immune responses to vascularized allografts and would be an important target for immune intervention.

Angiotensin-converting enzyme inhibitor-induced anemia and treatment for erythrocytosis in renal transplant recipients

Erythrocytosis is not rare in renal transplant recipients, and phlebotomy is still the main treatment. Recently, the occurrence of angiotensin-converting enzyme (ACE) inhibitor induced anemia in patients on chronic hemodialysis and in renal transplant recipients has been reported. We herein report 5 transplant recipients whose hematocrit levels decreased while taking ACE inhibitors, including 2 patients treated with ACE inhibitors for erythrocytosis. The individual mean hematocrit values ranged from 35.0% to 54.7% before treatment and from 27.6% to 42.0% after treatment. The hematocrit level in the 2 patients with erythrocytosis decreased from 54.7% to 39.8% and 47.5% to 27.6%, respectively. Anemia improved after discontinuation or dosage reduction of the drugs. The patients were given the same immunosuppressive drugs, and had good renal function. ACE inhibitor-induced conspicuous anemia was not observed in the transplant recipient who received a kidney from a twin sibling and had not been taking any immunosuppressive drugs, nor in the 8 other patients with diabetes mellitus or chronic glomerulonephritis who served as controls. We conclude that ACE inhibitor-induced anemia may frequently arise in an immunosuppressed state. Based on these events, the ACE inhibitor can be used as a potent drug for erythrocytosis in post-transplant recipients.

[Acute pulmonary embolism after radical operation for renal cell carcinoma with vena caval extension: a case cured by thrombolytic therapy]

A 54-year-old man was hospitalized for a right renal tumor with intraluminal extension into the vena cava. He underwent radical nephrectomy with thrombectomy and regional lymphadenectomy. On the 8th postoperative day, he suddenly complained of dyspnea with tachypnea and cyanosis. Arterial blood gas analyses under an oxygen flow of 4L/min revealed PaO2 32.1 mmHg. Pulmonary angiography revealed filling defects in the right main pulmonary artery and left descending branch. Under the diagnosis of acute pulmonary embolism, thrombolytic and anti-coagulation therapy was performed and the patient recovered from the disease. We should be aware of pulmonary embolism as a postoperative complication of urological surgery.

The effects of intraportal prostaglandin E1 administration on hepatic warm ischemia and reperfusion injury in dogs

To determine the route of prostaglandin E1 (PGE1) administration which would have the greatest protective effect against hepatic warm ischemia, two experiments were performed using dogs. The pharmacokinetics of PGE1 were investigated in a preliminary study, after which, the effects of PGE1 in a 90-min warm ischemic liver model were examined. The dogs were divided into three groups of ten, according to the treatment given: group A was an untreated control group, group B received PGE1 intravenously, and group C received PGE1 intraportally. The PGE1 was infused continuously at a rate of 0.02 microliters/kg/min before and after ischemia. All the dogs in groups A and B died within 24 h of induced ischemia. Whereas, six of the ten dogs in group C survived for over 3 days. The arterial ketone body ratio was not maintained in groups A and B, but it was in group C. Furthermore, in group C the serum lipid peroxide level, which reflects hepatocellular membrane damage, was maintained at a lower level than that in the other groups after ischemia. Electron microscopy revealed sinusoid destruction and changes in both the plasma membrane and parenchymal cell mitochondria in groups A and B, while in group C these structures were well preserved. These findings confirmed that intraportally administered PGE1 improved the hepatic microcirculation and stabilized the hepatocellular membranes. Our results indicate that intraportal administration of PGE1 has a greater protective effect than intravenous administration against warm ischemic liver injury.

The effect of intraportal PGE1 on warm ischemic liver damage

To determine the most effective route of administering prostaglandin E1 (PGE1) to inhibit warm ischemic liver damage, 90-min warm ischemia was established in a canine model. The dogs were divided into three groups according to the treatment given. Thus, group A (n = 10) was the control group which received no treatment, group B (n = 7) was administered PGE1 intravenously, and group C (n = 7) was administered PGE1 intraportally. PGE1 was continuously administered before and after the ischemia at a rate of 0.02 microgram/kg/min. The branched-chain amino acid to aromatic amino acid ratio in the hepatic vein, and the arterial ketone body ratio of acetoacetic acid to beta-hydroxybutyric acid, were examined to observe the metabolism of each amino acid and the oxidation-reduction ability of hepatocytes. Both ratios were maintained only in the group C dogs, three of which survived for over 3 days, whereas in groups A and B, all the dogs died within 24 h. The results of this study imply that the intraportal administration of PGE1 was more effective against warm ischemic liver damage than the intravenous administration of PGE1.

[A case of scrotal bladder hernia containing bladder cancer]

A 70-year-old man had a history of total laryngectomy for laryngeal cancer and bilateral inguinal hernia repair 5 years previously. The patient had suffered from difficulty with urination since then and had been treated for prostatic hypertrophy at our department. He developed microscopic hematuria from June 1991, and was admitted because a bladder tumor was detected by cystoscopy. Cystography showed a scrotal bladder hernia with filling defects in the bladder per se and the bladder hernia as well. Cystoscopy revealed tumors in the hernia and in the vicinity of the ureteral orifice. Biopsy indicated transitional cell carcinoma. Voiding cystourethrography showed normal urination and no residual urine. Excision of the tumor-containing hernia, partial cystectomy with right ureteral orifice, and reconstruction of the right inguinal canal were performed on October 25, 1991. The postoperative course was favorable and he was discharged on the 40th postoperative day. The tumors were respectively stage as TCC, G1, and pT1a, and TCC, G1 greater than G2, and pT1b. Thirty five cases of bladder hernia that have been reported in Japan. Eight cases of accompanied by cancer have been reported in Japanese (3 cases) and foreign (5 cases) literatures. These are reviewed and discussed.

[Continuous hyperthermic peritoneal perfusion (CHPP) therapy in advanced gastric cancer]

In CHPP therapy for advanced gastric cancer, a perfusate containing 20 mg CDDP and 8 mg MMC in 1,000 ml physiologic saline warmed at 47 degrees C was infused at a constant rate of 200 ml/min into the pouch of Douglas. The intraperitoneal temperature at the supra-pancreatic region was around 39.0 degrees C. To obtain a more stable and higher intraperitoneal temperature, the infusing rate was increased to 400 ml/min. This yielded a 3 degrees C higher temperature (42 degrees C) at the same measuring site. However, the temperature recorded at various intraperitoneal sites did not always reach such an effective range. The maximal plasma concentrations of MMC determined during CHPP at the 200 and 400 ml/min infusion were 0.09 +/- 0.03 and 0.11 +/- 0.03 microgram/ml, and those of CDDP 1.6 +/- 0.4 and 1.7 +/- 0.3 microgram/ml, respectively, all of which were not significantly different. When an intraperitoneal dosage of 20 mg MMC was given to 3 patients, the portal venous blood, at 10 min after the administration, produced a 1.7 times higher concentration of the agent than did the peripheral venous blood. This discrepancy between the two concentrations was much smaller than found by other investigators in animal experiments.

[Application of fluoro-resins on the tissue surface of pontic]

The purpose of this study was to investigate the applicability of fluoro-composite resins for clinical usage. Polychlorotrifluoroethylene (PCTFE) resin was applied to the tissue surface of pontic for 7 days in the oral cavity, and the amount of plaque accumulation was measured. The plaque retaining capacity of PCTFE was compared with Au-Ag-Pd alloy and porcelain. In order to survey the endurance of PCTFE-resin, the surface of PCTFE-coating was observed under SEM. The results were as follows: 1. Plaque accumulation on the PCTFE-coating was less than that of metal, and was equivalent to or less than that of porcelain. 2. Pin-point like plaque formation similar to that found on porcelain surfaces were observed on the PCTFE-coating. 3. SEM observations of the PCTFE-coating revealed some traces made by the toothbrush. As a result, PCTFE-coating was found to be useful for decreasing the amount of plaque formation on those pontic surfaces where mechanical cleaning can not be maintained.

[Practical application of diamond points in mucosalplasty of edentulous ridges]

In order to establish a new operative method of mucosalplasty in the edentulous ridges to improve pontic adaptation, newly revised diamond points were produced and tested. The efficiency of these diamond points were tested on the edentulous ridges of dogs in relation to its shape, size of the diamond particle, and appropriate rotational speed, and the tissue damages and healing processes were observed under a light microscope and SEM. The results were as follows: 1. Light microscopic observations showed immediate post operative necrosis of the wound surface, and degeneration below the necrosed layer of high rotational speed diamond points. 2. Tissue damage became larger as the size of the diamond particle increased, but there appeared to be no influence upon the healing process of the wound. 3. Tissue damage also became larger as the diameter of the diamond point increased, but again no influence upon the healing process was observed. 4. Middle to low rotational speeds showed no differences in tissue damage or wound healing, but high rotation caused larger tissue damage and prolongation in the healing process. 5. The most suitable condition for mucosalplasty revealed the size of the diamond particle to be 200 microns, and rotational speed to be between 12,000-20,000 rpm.

[Rhabdomyosarcoma of the prostate: report of a case and review of the literature]

Rhabdomyosarcoma of the prostate is a rare tumor and its prognosis is extremely poor. However, the survival rate has been gradually improved by using combined chemotherapy. A 17-year-old man with the chief complaint of dysuria was referred to our hospital on April 7, 1986. Prostatic needle biopsy was performed and pathological diagnosis was rhabdomyosarcoma of the prostate. The patient was given preoperative combined chemotherapy consisting of actinomycin D and cyclophosphamide. Total cystoprostaurethrectomy and ileal conduit were performed on April 30, 1986. He underwent postoperative combined chemotherapy (vincristine, actinomycin D, cyclophosphamide). He is well 13 months after his initial symptoms and is clinically free of tumor 12 months postoperatively. Forty-two cases of rhabdomyosarcoma of the prostate including our case were collected from the Japanese literature and reviewed with respect to the multimodal treatment and prognosis.