Graft Survival In Combinations Research Articles

Grafting technique and rootstock species for the propagation of Plinia cauliflora

ABSTRACT: One of the biggest challenges for expansion of jabuticaba fruit tree cultivation is the high cost of seedlings due to to difficulties with vegetative propagation. Here, we aimed to evaluate graft survival in combinations of Plinia cauliflora and rootstocks of other species from the Myrtaceae family. The study was carried out at the Universidade Tecnológica Federal do Paraná - Campus Dois Vizinhos, Paraná State, Brazil. Eugenia uniflora L., E. involucrata DC, and P. cauliflora were used as rootstocks and were obtained as seeds. The 'whip-and- tongue' and cleft grafting techniques were tested for vegetative propagation. Grafted plants were cultivated in a greenhouse. The experimental design was a randomized complete block, in factorial 3×2 (rootstock species× graft type), with four replicates of 10 grafts by plot. Compatibility between rootstock species and scion was evaluated by diameter growth below and above the grafting point and by vegetative budburst and survival percentages. The use of P. cauliflora grafts with the same species was required for propagation. E. involucrata and E. uniflora rootstocks were not capable of propagation with P. cauliflora . Therefore, it is necessary to test other species from the Myrtaceae family.

Effects of platelet-rich plasma, adipose-derived stem cells, and stromal vascular fraction on the survival of human transplanted adipose tissue.

Traditional adipose tissue transplantation has unpredictable viability and poor absorption rates. Recent studies have reported that treatment with platelet-rich plasma (PRP), adipose-derived stem cells (ASCs), and stromal vascular fraction (SVF) are related to increased survival of grafted adipose tissue. This study was the first simultaneous comparison of graft survival in combination with PRP, ASCs, and SVF. Adipose tissues were mixed with each other, injected subcutaneously into the back of nude mice, and evaluated at 4, 8, and 12 weeks. Human adipocytes were grossly maintained in the ASCs and SVF mixtures. Survival of the adipose tissues with PRP was observed at 4 weeks and with SVF at 8 and 12 weeks. At 12 weeks, volume reduction in the ASCs and SVF mixtures were 36.9% and 32.1%, respectively, which were significantly different from that of the control group without adjuvant treatment, 51.0%. Neovascular structures were rarely observed in any of the groups. Our results suggest that the technique of adding ASCs or SVF to transplanted adipose tissue might be more effective than the conventional grafting method. An autologous adipose tissue graft in combination with ASCs or SVF may potentially contribute to stabilization of engraftment.

Blockade of Notch Ligand Delta1 Promotes Allograft Survival by Inhibiting Alloreactive Th1 Cells and Cytotoxic T Cell Generation

The Notch signaling pathway has been recently shown to contribute to T cell differentiation in vitro. However, the in vivo function of Notch signaling in transplantation remains unknown. In this study, we investigated the importance of Delta1 in regulating the alloimmune response in vivo. Delta1 expression was upregulated on dendritic cells and monocytes/macrophages upon transplantation in a BALB/c into B6 vascularized cardiac transplant model. Whereas administration of anti-Delta1 mAb only slightly delayed survival of cardiac allografts in this fully MHC-mismatched model, it significantly prolonged graft survival in combination with single-dose CTLA4-Ig or in CD28 knockout recipients. The prolongation of allograft survival was associated with Th2 polarization and a decrease in Th1 and granzyme B-producing cytotoxic T cells. The survival benefit of Delta1 blockade was abrogated after IL-4 neutralization and in STAT6KO recipients, but was maintained in STAT4KO recipients, reinforcing the key role of Th2 cell development in its graft-prolonging effects. To our knowledge, these data demonstrate for the first time an important role of Delta1 in alloimmunity, identifying Delta1 ligand as a potential novel target for immunomodulation in transplantation.

INHIBITION OF RENAL ALLOGRAFT REJECTION BY BLOCKING THE COSTIMULATORY PATHWAY IN PRIMATES

229 Clinical organ transplantation is successful as reflected by high percentages of graft survival at one year after transplantation. However the occurrence of (irreversible) graft rejection episodes together with chronic rejection remain a major clinical problem. The ultimate goal in transplantation is to give a (relatively) short conditioning treatment around the time of transplantation which will result in permanent graft acceptance without further immunosuppression. There is accumulating evidence that blocking the costimulatory pathways, CD80/CD86 - CD28/CTLA4 and CD40L - CD40 offer such a valid approach. The efficacy of anti-CD80, anti-CD86 and anti-CD40 was examined as a prophylactic treatment to prevent rejection in a life-supporting kidney transplant model in rhesus monkeys. The kidney function was monitored by serum creatinin. The mean survival time of untreated kidney-transplanted rhesus monkeys is 6 days. Short term treatment (14 days) with either anti-CD80 and anti-CD86 alone or in combination with anti-CD40 mAb resulted in a significant prolonged survival (19-35 days). Long term treatment (28 days) with all three mAb resulted in a prolonged survival of 35 - 52 days. During the treatment period no signs of rejection or side-effects were noted. Kidney graft rejection started after the antibody therapy was stopped. The induction of the anti-antibody was significantly delayed using the triple therapy as compared to the use of anti-CD80 and anti-CD86 mAb alone. In addition the donor specific allo-antibody response was determined. The anti-donor antibody response was also delayed or absent in animals treated with anti-CD80, CD86 and CD40 as compared to animals treated with anti-CD80 and anti-CD86 mAb alone This demonstrated a significant inhibitory effect on the B cell response after addition of anti-CD40. But, the combination of anti-CD80 and anti-CD86 mAb without anti-CD40 mAb or CsA resulted in less signs of acute and chronic vascular rejection. Thus, prolonged graft survival in combination with reduced B cell response and reduced signs of graft vascular disease can be achieved by blocking the costimulatory pathways. This clearly demonstrates the potential of this strategy to be used as a new immunosuppressive regimen in transplant medicine.