Shown are the proportions (%) of splenocyte-derived CD4+ (A), CD8+ (B), CD69+ (C) and CD4+/CD25+ (D) T cells in recipient C57BL/6 mice treated with the indicated immunosuppressive regimens. mice were treated with either Ros A, MR1, or both (the “double” treatment). Allograft survival was prolonged in the double-treated AZD9898 animals compared to animals that received only Ros A or MR1. As is the case with the single-treated animals at 15 days after transplantation, the double-treated recipients did not display a significant decrease in the expression of cytokines or the population of activated T cells. Infiltrating CD3+ T cells were reduced in the MR1- or double therapy relative to AZD9898 control or RosA group. However, at the same time point, double-treated graft showed fewer apoptotic cells and increased expression of insulin and glucagons, compared to the single-treatment groups. Furthermore, long-term ( 150 days) allografts that were received with double therapy exhibited larger islet clusters and contained more insulin- and glucagon-positive cells, relative to the MR1-treated grafts. In conclusion, treatment with both Ros A and MR1 has a synergistic effect in murine islet allotransplantation. values 0.05 were considered to be statistically significant. Results Prolonged survival of islet allografts in B6 mice with chemically induced diabetes After transplantation of allogeneic islets (300 IEQ) into the diabetic mice, all recipients became normoglycemic within 1 day after transplantation, and no recipients were lost because of primary non-functioning transplants (Figure 1A). Open in a separate window Figure 1 Effect of islet transplantation on glucose tolerance and graft survival. Shown are (A) the mean plasma glucose concentration [Glucose concen. (mg/dl)] and (B) the percent graft survival [Graft survival (%)] in diabetic mice that underwent allogeneic mouse islet transplantations. In order to confirm long-term graft function and acceptance, normoglycemic mice underwent unilateral nephrectomys of the graft-bearing kidneys at the time points indicated by arrows in (A) and (B). To examine the effect of immunosuppression on survival of the islet grafts, diabetic transplant recipient mice were assigned to 1 1 of 4 different organizations ( 5) relating to their immunosuppressive treatment regimens. The grafts in the group of mice that received no immunosuppressive treatment (control) were invariably lost within about 50 days [Median graft survival time (MST) = 44 days; 0% graft survival after 47 days] (Number 1B). The group of mice that received a short treatment with Ros A only showed a MST = 53 days (0% ALRH graft survival after 121 days), AZD9898 and the group treated with only MR1 displayed a significant prolongation of graft survival, relative to the control and Ros A only organizations (MST = 82; 33% AZD9898 graft survival after 150 days). In contrast, administration of the double therapy (Ros A plus MR1) led to a remarkable prolongation of 100% graft survival ( 160 days), which constituted a significant difference (= 0.011) between the double-treated and MR1-alone therapy organizations. The graft-bearing kidneys from long-term graft-bearing mice were removed 164 days after transplantation in order to confirm allograft acceptance. After nephrectomy, the allografts were maintained in tradition, upon which their survival plummeted (Number 1B). At the same time, a recurrence of hyperglycemia was obvious in the nephrectomized mice (Number 1A), which suggests the diabetic condition was reversed by islet transplantation and reappeared when the graft was eliminated. Glucose tolerance of islet allografts To study the effect of transplanted islets within the whole-body glucose disposal rate, IPGTTs were performed on short- and long-term functioning islet recipients at 15, 85, 123, and 153 days after transplantation. As demonstrated in Number 2, in response to an IP injection of a high dose of glucose (2 g/kg), the elevated blood glucose concentrations in recipients were restored to the normal range within 2 h. The amplitude of the blood glucose induction and the kinetics of blood glucose decline did not AZD9898 differ significantly among the treatment organizations. Open in a separate window Number 2 Intraperitoneal glucose tolerance test (IPGTT) following allogeneic.
- T-cell epitopes are peptides derived from antigens and identified by the T-cell receptor (TCR) when bound to MHC molecules displayed within the cell surface of APCs
- Cloning of gene fragments encoding diagnostic antigens
- Epitopes are present on a single HLA (private epitope) or shared by multiple antigens (public epitope)
- Spleens were harvested in 1 (C) or 2 wpi (B, C) and cells were analyzed by movement cytometry in comparison to na?ve mice
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