-
[show abstract]
[hide abstract]
ABSTRACT: BACKGROUND: T-cell receptor Vδ2 γδ T cells (Vδ2 cells) participate in host defense, whereas Vδ1 γδ T cells (Vδ1 cells) may regulate immune responses. Vδ1 cells appear to play a role in fetomaternal tolerance and our aim was to examine their role in liver transplant tolerance. METHODS: To determine whether Vδ1 cells increase within accepted grafts after semiallogeneic pediatric liver transplantation, the Vδ1/Vδ2 ratio was assessed at the transcriptional level and the complementarity-determining region 3 loop of the δ chain of Vδ1 cells was sequenced in biopsies from immunosuppression-free (n=6) or almost free (n=3) liver transplant recipients, referred to as group tolerance (Gr-Tol; n=9). The results were compared with biopsies from grafts of recipients on maintenance immunosuppression due to concern of rejection (Gr-IS; n=11). Chronically rejected grafts (Gr-CR; n=6) and normal livers (Gr-NL; n=8) were also examined. RESULTS: The Vδ1/Vδ2 ratio was the highest in Gr-Tol (0.07±0.06) compared with Gr-IS (0.03±0.02; P=0.04), Gr-CR (0.01±0.02; P=0.008), and Gr-NL (0.02±0.04; P=0.01). There was an identical complementarity-determining region 3 sequence (100% homologous) among all recipients in Gr-Tol, which was dominant in six of nine recipients. This sequence was not seen in Gr-IS or Gr-CR, although it was observed in five of six normal livers. CONCLUSIONS: A unique Vδ1-bearing T-cell clone accumulates within accepted human liver grafts. It might be useful as a biomarker of tolerance and the identification of its ligand might aid in the development of a novel strategy for tolerance induction.
Transplantation 12/2012; · 4.00 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: It is a matter of great importance in a donation after cardiac death to attenuate ischemia-reperfusion injury (IRI) related to the inevitable warm ischemic time.
Donor dogs were rendered cardiac-dead and left at room temperature. The dogs were allocated into 2 groups: the β-2 group (n = 5) received an aerosolized β-2 adrenoreceptor agonist (procaterol, 350 μg) and ventilation with 100% oxygen for 60 minutes starting at 240 minutes after cardiac arrest, and the control group (n = 6) received an aerosolized control solvent with the ventilation. Lungs were recovered 300 minutes after cardiac arrest. Recipient dogs underwent left single-lung transplantation to evaluate the functions of the left transplanted lung for 240 minutes after the reperfusion.
Oxygenation and dynamic compliance were significantly higher in the β-2 group than in the control group. The β-2 group revealed significantly higher levels of cyclic adenosine monophosphate and high-energy phosphates in the donor lung after the inhalation than before it. Histologic findings revealed that the β-2 group had less edema and fewer inflammatory cells.
Our results suggest that β-2 adrenoreceptor agonist inhalation during the pre-procurement period may ameliorate IRI.
The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 04/2012; 31(7):773-9. · 3.54 Impact Factor
-
Hidenori Ohe,
Kayo Waki,
Mami Yoshitomi,
Takeshi Morimoto,
Hanaa Nafady-Hego,
Naoki Satoda,
Ying Li, Xiangdong Zhao,
Shimon Sakaguchi,
Shinji Uemoto,
G Alex Bishop,
Takaaki Koshiba
[show abstract]
[hide abstract]
ABSTRACT: Pediatric recipients of living-donor liver transplants (LDLT) can often discontinue immunosuppression (IS). We examined factors affecting development of operational tolerance (OT), defined as off IS for >1 year, in this population. A historic cohort analysis was conducted in 134 pediatric primary semi-allogeneic LDLT. Multivariate logistic regression analysis was used. The frequency of peripheral regulatory T cells (Tregs) was determined at >10 years post-Tx by FACS analysis. IS was successfully discontinued in 84 tolerant patients (Gr-tol), but not in 50 intolerant patients (Gr-intol). The Gr-intol consisted of 24 patients with rejection (Gr-rej) and 26 with fibrosis of grafts (Gr-fib). The absence of early rejection [odds ratio (OR) 2.79, 95% CI 1.11-7.02, P = 0.03], was a positive independent predictor, whereas HLA-A mismatch (0.18, 0.03-0.91, P = 0.04) was a negative predictor. HLA-DR mismatches did not affect OT. The Treg frequency was significantly decreased in Gr-intol (4.9%) compared with Gr-tol (7.6%) (P = 0.003). There were increased levels of tacrolimus in the first week in Gr-Tol (P = 0.02). Although HLA-B mismatch (8.73, 1.09-70.0, P = 0.04) was a positive independent predictor of OT, its clinical significance remains doubtful. In this large cohort of pediatric LDLT recipients, absence of early rejection, HLA-A match and the later predominance of Tregs are factors associated with OT.
Transplant International 11/2011; 25(1):97-106. · 2.92 Impact Factor
-
Jin Sakamoto,
Fengshi Chen,
Tetsu Yamada,
Daisuke Nakajima,
Akihiro Ohsumi,
Ryutaro Kikuchi, Xiangdong Zhao,
Takuji Fujinaga,
Tsuyoshi Shoji,
Hiroaki Sakai,
Toru Bando,
Hiroshi Date
[show abstract]
[hide abstract]
ABSTRACT: One method of countering chronic lung donor shortages is the practice of donation after cardiac death (DCD). However, this technique inevitably leads to pulmonary dysfunction related to warm ischemia. One promising method of alleviating this problem is ventilation. However, it can rarely be initiated from the onset of cardiac arrest, particularly in uncontrolled DCD donors. We investigated the protective effect of the last 60 min of ventilation during a 240-min warm ischemic time.
We rendered donor dogs cardiac dead and left them at room temperature. Six dogs received ventilation with 100% oxygen for 60 min starting at 180 min after cardiac arrest (ventilation group). Eight dogs received no ventilation. Lungs were harvested 240 min after cardiac arrest, then transplanted into recipient dogs. At 60 min after reperfusion, the right pulmonary artery was ligated, and the function of the left transplanted lung was evaluated.
In the ventilation group, all six animals survived for 240 min after reperfusion, whereas in the nonventilation group, only four of eight survived. The ventilation group demonstrated significantly better pulmonary oxygenation, shunt fraction, and wet-to-dry weight ratio. Furthermore, the ventilation group revealed significantly higher levels of high-energy phosphates in the lung tissues, fewer apoptotic cells, lower levels of tumor necrosis factor-α and interleukin-8 messenger RNA in the lung tissues, and lower levels of interleukin-6 messenger RNA in the serum.
Our results suggest that ventilation during the late phase of the preprocurement period may ameliorate ischemia-reperfusion injury in DCD donors.
Transplantation 08/2011; 92(8):864-70. · 4.00 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: CD4+CD25++CD45RA+ cells (naïve regulatory T cells [naïve-Tregs]) have been identified as a functionally premature form of CD4+CD25+++CD45RA(-) cells (conventional-Tregs). However, their contribution to transplant tolerance remains to be elucidated.
We examined the frequency and the function of conventional and naive-Tregs in the peripheral blood derived from operationally tolerant patients after pediatric living-donor liver transplant (Gr-tol). The data were compared with those of patients who were unable to be weaned off immunosuppression due to rejection (group-intolerance [Gr-intol]), patients in the process of weaning immunosuppression (Gr-weaning) and healthy volunteers (group-healthy volunteers [Gr-vol]).
In Gr-tol, the frequency of conventional-Tregs was significantly higher than that in Gr-vol and tended to be higher than that in Gr-intol. The frequency of naive-Tregs was significantly decreased in Gr-intol versus those in Gr-tol, -weaning, and -vol. In mixed lymphocyte reactions, donor-specific hyporesponsiveness of CD4+ cells was observed only in Gr-tol but not in the other groups. Depletion of conventional or naive-Tregs from CD4+ cells demonstrated that the suppressive properties of donor antigen-reactive conventional and naïve-Tregs were upregulated compared with those of third-party antigen-reactive conventional and naïve-Tregs in Gr-tol only.
This is the first report providing detailed evidence that donor-specific naïve-Tregs were generated and their suppressive properties were upregulated in the peripheral blood of tolerant patients, whereas their frequency was downregulated in intolerant patients. Therefore, we speculate that not only conventional-Tregs play a role in Tx tolerance but also the role of naïve-Tregs is critical.
Transplantation 11/2010; 90(12):1547-55. · 4.00 Impact Factor
-
Tomohide Hori,
Justin H Nguyen, Xiangdong Zhao,
Yasuhiro Ogura,
Toshiyuki Hata,
Shintaro Yagi,
Feng Chen,
Ann-Marie T Baine,
Norifumi Ohashi,
Christopher B Eckman, [......],
Kagemasa Kuribayashi,
Takuma Kato,
Kanako Saito,
Linan Wang,
Mie Torii,
Naruhiko Sahara,
Naoko Kamo,
Tomoko Sahara,
Motohiko Yasutomi,
Shinji Uemoto
[show abstract]
[hide abstract]
ABSTRACT: To investigate our learning curves of orthotopic liver transplantation (OLT) in rats and the most important factor for successful surgery.
We describe the surgical procedures for our rat OLT model, and determined the operator learning curves. The various factors that contributed to successful surgery were determined. The most important surgical factors were evaluated between successful and unsuccessful surgeries.
Learning curve data indicated that 50 cases were required for operator training to start a study. Operative time, blood loss, warm ischemic time, anhepatic phase, unstable systemic hemodynamic state, and body temperature after surgery significantly affected surgery success by univariate analysis, while the anhepatic phase was the most critical factor for success by multivariate analysis.
OLT in rats is the only liver transplantation model that provides clinically relevant and reliable results. Shortened anhepatic phase is key to success in this model.
World Journal of Gastroenterology 07/2010; 16(25):3120-32. · 2.47 Impact Factor
-
Mami Yoshitomi,
Takaaki Koshiba,
Hironori Haga,
Ying Li, Xiangdong Zhao,
Donghua Cheng,
Aya Miyagawa,
Hiromi Sakashita,
Tatsuaki Tsuruyama,
Hidenori Ohe,
Mikiko Ueda,
Shinya Okamoto,
Hiroto Egawa,
Kathryn Wood,
Shimon Sakaguchi,
Toshiaki Manabe,
Koichi Tanaka,
Shinji Uemoto
[show abstract]
[hide abstract]
ABSTRACT: Operational tolerance is defined as long-term acceptance of a transplanted organ after complete cessation of immunosuppression (IS), but may not always protect against antigen-dependent changes in graft morphology.
IS free patients after living-donor liver transplantation (LDLT) underwent protocol biopsy (tolerance group [Gr-Tol]) and were evaluated for rejection and fibrosis. The degree of fibrosis was compared with those in the patients on maintenance IS group (Gr-IS) and the base line normal liver group (Gr-BS). When bridging fibrosis or progression of fibrosis was observed, IS was reintroduced or increased in Gr-Tol or in the patients in the weaning process.
Neither acute nor chronic rejection was observed. The degree of fibrosis, however, was significantly greater in Gr-Tol than those in Gr-IS and Gr-BS. In Gr-Tol, the number of graft infiltrating FOXP3 cells was significantly increased, the interval between LDLT and biopsy plus the donor age was significantly longer, and recipient age at LDLT was significantly younger, compared with those in Gr-IS. However, none of these three parameters correlated with the degree of fibrosis. In 7 of 11 patients in whom IS was reintroduced or increased, the improvement of fibrosis was observed by the subsequent biopsy.
Grafts of operationally tolerant patients after LDLT did not exhibit acute or chronic rejection, but they exhibited fibrosis. It remains elusive whether fibrosis observed in tolerant grafts is antigen dependent. The finding that after [corrected] the reintroduction or the increase of IS fibrosis was improved supported the possibility that fibrosis in operationally tolerant patients was antigen dependent.
Transplantation 03/2009; 87(4):606-14. · 4.00 Impact Factor
-
Jitian Zhang,
Fengshi Chen, Xiangdong Zhao,
Akihiro Aoyama,
Toshihiro Okamoto,
Takuji Fujinaga,
Tsuyoshi Shoji,
Hiroaki Sakai,
Youbin Cui,
Toru Bando,
Hiroshi Date
[show abstract]
[hide abstract]
ABSTRACT: The control of warm ischemia-reperfusion injury is crucial in managing donors after cardiac death for lung transplantation. We focused on transalveolar administration as a drug-delivery route for such donors. Milrinone is a phosphodiesterase 3 inhibitor that inhibits the breakdown of cyclic adenosine monophosphate and selectively relaxes smooth muscle. We hypothesized that nebulized milrinone would mitigate warm ischemia-reperfusion injury of lung.
This study was conducted with an isolated rat lung perfusion model. Lungs were excised, exposed to 55-minute ischemia at 37 degrees C, and reperfused for 60 minutes. During ischemia, nebulized milrinone (n = 6) or saline (n = 6) was inhaled. Lungs were continuously perfused without ischemia as a sham group (n = 6). Airway resistance, pulmonary vascular resistance, pulmonary compliance, weight gain and blood gas were measured. Adenine nucleotide levels and apoptosis were investigated in the reperfused lungs.
Milrinone nebulization decreased post-ischemic pulmonary vascular resistance (0.98 +/- 0.05 and 1.74 +/- 0.17 cm H(2)O/ml.min at 60 minutes of reperfusion in the milrinone and control groups, respectively [p < 0.01]). It did not alter cyclic adenosine monophosphate levels, but it did elevate adenosine triphosphate levels (9.87 +/- 0.38 and 6.91 +/- 0.45 in the milrinone and control groups, respectively [p < 0.01]) and suppressed apoptosis (3.83 +/- 0.91 and 46.17 +/- 3.39 of mean apoptotic cell numbers in the milrinone and control groups, respectively [p < 0.01]).
Milrinone nebulization decreased post-ischemic pulmonary vascular resistance, elevated adenosine triphosphate levels, and suppressed apoptosis. Nebulized milrinone has some protective effects against warm ischemia.
The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 02/2009; 28(1):79-84. · 3.54 Impact Factor
-
Naoki Satoda,
Tsuyoshi Shoji,
Yanling Wu,
Takuji Fujinaga,
Fengshi Chen,
Akihiro Aoyama,
Ji Tian Zhang,
Ayuko Takahashi,
Toshihiro Okamoto,
Izumi Matsumoto, [......],
Toshiaki Manabe,
Eiji Kobayashi,
Shimon Sakaguchi,
Hiromi Wada,
Hidenori Ohe,
Shinji Uemoto,
Junichi Tottori,
Toru Bando,
Hiroshi Date,
Takaaki Koshiba
[show abstract]
[hide abstract]
ABSTRACT: Outcome for highly immunogenic lung transplantation remains unsatisfactory despite the development of potent immunosuppressants. The poor outcome may be the result of a lack of minimally invasive methods to detect early rejection. There is emerging clinical evidence that, paradoxically, expression of forkhead box P3 (FOXP3, a specific marker for the regulatory T cells) is upregulated within rejecting grafts.
Orthotopic lung transplantation was performed using miniature swine without immunosuppression. Rejection was monitored by chest radiography and open lung biopsy. Expressions levels of FOXP3, perforin, Fas-L and IP-10 mRNA were quantified in the peripheral blood. In addition, rescue immunosuppressive therapy (steroid plus tacrolimus) was administered on post-operative day (POD) 4 or 6.
Early rejection was detected by open lung biopsy, but misdiagnosed by chest radiography on POD 4. Expression of FOXP3 in the peripheral blood reached its highest value as early as POD 4, followed by a decline. Such an increase of FOXP3 was not observed in recipients given high-dose tacrolimus. Neither perforin, Fas-L or IP-10 in the peripheral blood exhibited significant fluctuations in the early phase of rejection. Rescue immunosuppressive therapy from POD 4, when peak FOXP3 was seen, prolonged graft survival (27.2 days, versus 9.1 days without immunosuppression, p < 0.001), in contrast to POD 6, when rejection was suspected by chest radiography (11.5 days, p = not statistically significant [NS]).
In a miniature swine lung transplantation model, the FOXP3 mRNA level in the peripheral blood was upregulated at an early phase of rejection. The clinical implication of this finding remains to be elucidated.
The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 01/2009; 27(12):1293-301. · 3.54 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Some experimental transplant-tolerance models have shown that the presence of regulatory T cells within grafts is important for the development of tolerance (Tol). METHODS.: To determine if the presence of regulatory T cells correlates with graft acceptance in living-donor liver-transplantation tolerance, the expression of Foxp3 mRNA and the presence of CD4, CD8, and Foxp3 cells were quantified in biopsies from tolerant recipients by real-time polymerase chain reaction and by immunohistochemistry and immunofluorescent staining (Gr-Tol). The results were compared with biopsies from the recipients on maintenance immunosuppression (Gr-IS), grafts removed because of chronic rejection (Gr-CR), or normal liver (Gr-NL).
The expression of Foxp3 mRNA in Gr-Tol was higher than that in Gr-IS (P=0.07) and Gr-NL (P<0.0001), but equivalent to that in Gr-CR. In Gr-Tol, Foxp3 cells were detectable within the clustered CD4 and CD8 cells in the portal areas. Ninety-two percent of those Foxp3 cells were CD4, whereas 8% were CD8. The number of Foxp3 cells was significantly increased in Gr-Tol, compared with that in Gr-IS (P<0.05), although the number of CD4 or CD8 cells did not differ between the two. Foxp3 cells were hardly detectable in Gr-CR or -NL.
This is the first report showing that CD4Foxp3 cells are present within grafts in a subset of tolerant patients after human liver transplantation. A prospective study is needed to elucidate whether the assessment of intragraft expression of Foxp3 protein, but not Foxp3 mRNA, can aid the identification of living-donor liver-transplantation recipients who can successfully withdraw IS.
Transplantation 12/2008; 86(12):1837-43. · 4.00 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: ET-Kyoto solution (ET-K) is an extracellular-type organ preservation solution containing the cytoprotective disaccharide, trehalose. A previous study reported the supplement of dibutyryl cyclic adenosine monophosphate (db-cAMP) in conventional ET-K to attenuate lung ischemia-reperfusion injury. In this study, the efficacy of this modified ET-K for liver preservation was investigated by comparison with University of Wisconsin solution (UW). ET-K was supplemented with db-cAMP (2 mmol/L). Lewis rats were randomly assigned to two groups, and liver grafts were flushed and stored at 40C for 24 h with ET-K or UW before syngeneic liver transplantation. The graft function and histological changes at 4 h posttransplant as well as 7-day survival were evaluated. Recipient rat survival rate was significantly higher in the ET-K group than in the UW group. Preservation in ET-K resulted in a significant reduction in serum parenchymal transaminase level and promotion of bile production in comparison with UW. The serum hyaluronic acid level, an indicator of sinusoidal endothelial cell injury, was significantly lower after ET-K preservation than that in UW. Histologically, at 4 h after transplantation, the liver grafts preserved in UW solution demonstrated a greater degree of injury than those in ET-K, which appeared to be apoptosis, rather than necrosis. The continuity of the sinusoidal lining was better preserved in ET-K than in UW. In conclusion, ET-K supplemented with db-cAMP is superior to UW in rat liver preservation. This modified ET-K might therefore be a novel candidate for the procurement and preservation of multiple organs.
Cell Transplantation 02/2008; 17(1-2):99-109. · 5.13 Impact Factor
