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T G Markees

Publications and source records attributed to T G Markees.

29 records · Page 2Linked to original sources
PubMed1992

Prolonged adult skin allograft survival as a result of cotransplantation with neonatal tissue. The requirement for antigen sharing between graft and cotransplant.

The survival of an adult skin allograft can be prolonged by a cotransplant of neonatal, but not adult, skin on the same recipient. We demonstrated this phenomenon using a C3HeB/FeJ (H-2k; C3H) adult graft and neonatal cotransplant donors. The median survival time (MST) for adult graft survival on B6AF1 (H-2a/b) recipients was 59 days on recipients treated with antilymphocyte serum and donor bone marrow cells. With adult or neonatal cotransplants, the MSTs for adult graft survival were 55 and > 100 days, respectively. Our current experiments explore the specificity of this phenomenon by substituting neonatal cotransplants of several allogeneic and partially allogeneic strains. Cotransplants that do not share the antigens presented by the adult graft to the recipient as foreign do not produce any prolongation of adult graft survival. Thus, cotransplants of adult or neonatal C57BL/6J (H-2b) or A/J (H-2a) strain skins had no significant effect on adult C3H graft survival. In contrast to these results, neonatal (but not adult) cotransplants that share presented antigens produce a significant cotransplant effect. The presence, on a recipient, of a neonatal cotransplant of CBA/J (H-2k) resulted in significant prolongation of adult skin grafts (MST > 150 days; P < 0.05). As well, on a different recipient strain (CAF1; H-2a/d), neonatal C3H-H-2o2/SfSn (H-2o2) skin cotransplants, sharing only background antigens and H-2Dk with the adult graft donor, caused a significant prolongation of adult graft survival relative to that seen on recipients bearing only a single adult graft (MSTs = 53 and 31 days; P < 0.05). Our results suggest that this graft-prolonging effect of neonatal cotransplantation requires that the cotransplant shares antigens with the adult graft that are presented as foreign to the recipient.

Aging↗
PubMed1991

Induction of allograft tolerance with neonatal skin.

B6AF1 recipients treated with various combinations of ALS, CsA, and BMC were grafted with C3H skin from adult or neonatal donors. A survival advantage of neonatal skin compared with adult skin was clearly demonstrated in groups treated with ALS and CsA (median survival time [MST] = 89 days, neonatal skin; 50 days, adult skin), ALS and BMC, (MST = 92 days, neonatal; 64 days, adult skin), or with ALS only (MST = 55 days and 35 days, respectively). In these groups only neonatal grafts were observed to survive greater than 100 days. Also, once it was underway, rejection of the neonatal skin proceeded more slowly than that of adult skin. ALS/BMC/CsA treatment of adult skin recipients improved graft survival modestly (MST = 77 days, 20% of grafts surviving greater than 100 days). But neonatal graft survival was prolonged remarkably by the ALS/BMC/CsA treatment, with 95% of grafts surviving greater than 100 days and 84% surviving greater than 240 days. After bearing neonatal grafts for greater than 150 days, these mice were challenged with C3H adult skin grafts. The second grafts were uniformly accepted for greater than 135 additional days, but third-party grafts were rejected promptly. This specific tolerance could not be abrogated by injection of normal B6AF1 spleen cells, and rejection of the grafts by adoptively transferred sensitized cells was delayed (MST = 35 days). That the tolerance developed in response to grafting neonatal skin to ALS/BMC/CsA-treated recipients extends to adult tissue suggests that understanding of the immunoregulatory signal provided by the neonatal tissue might lead to a tolerogenic protocol for use with adult allografts.

Animals↗
PubMed1991

The effect of antilymphocyte serum, fractionated donor bone marrow, and cyclosporine on renal allograft survival in mongrel dogs.

The effect of combined treatment with antilymphocyte serum, fractionated donor bone marrow, and a limited course of cyclosporine on renal allograft survival in mongrel dogs was examined. Recipients were treated with ALS from day -5 to day +7, relative to transplantation on day 0 with an MLR-mismatched donor. Fractionated donor bone marrow cells (BMFr3) obtained by density gradient separation were infused 3-7 days after ALS treatment. CsA treatments were begun either 3-7 days after ALS plus BMFr3 infusion or 3-7 days after treatments with ALS alone. Extended allograft survival was achieved at all CsA doses in BMFr3-infused, ALS-treated recipients. Allografts were sustained throughout the CsA treatment period without rejection in the majority of recipients (6 of 8) receiving ALS plus BMFr3 and CsA at 20 Mg/kg/day for 60 days. By contrast, few grafts were sustained through 30 days of treatment with CsA at 3.2 (1 of 12) or 10 mg/kg/day (2 of 9) in ALS plus BMFr3-treated recipients. Cyclosporine treatment was ineffective at all doses in augmenting allograft prolongation in ALS-treated recipients that did not receive BMFr3. Nearly all (6 of 7) long-term survivors (greater than 180 days) were BMFr3-treated. Peripheral blood lymphocytes or bone marrow cells of these long-term survivors proliferated normally in response to Con A and PWM, and were MLR responsive to third-party cells but did not have reduced MLR responsiveness to donor alloantigen in all cases. These long-term survivors promptly rejected third-party renal allografts without adverse effects on the original transplant's function. These results show that long-term renal allograft survival with specific unresponsiveness to the donor can result from the combined treatment with ALS plus donor BMFr3 and a limited course of CsA.

Animals↗
PubMed1990

Prolongation of adult skin allograft survival by cotransplantation of neonatal skin in antilymphocyte serum and donor bone marrow cell-treated mice.

Adult male B6AF1 (H-2KIb/kDb/d) mice were given skin allografts from adult male C3H (H-2k) mice, with and without contralateral cotransplants. The cotransplants were of either adult or neonatal (less than 24 hr) C3H skin. In recipient mice treated peritransplantation with antilymphocyte serum and posttransplantation with an i.v. injection of donor-strain bone marrow cells, the presence of a neonatal cotransplant resulted in significantly longer survival of the adult grafts. Median survival time (MST) for adult grafts, for the group that received a neonatal cotransplant was greater than 100 days, in comparison to MSTs of 59 days and 55 days for the groups that received only single adult grafts or the adult graft with an adult cotransplant. These results suggest an active immunomodulatory contribution of neonatal tissue, and we term this phenomenon the "cotransplant effect." This prolongation of survival of the adult grafts by the neonatal cotransplants was statistically significant in animals treated with ALS and BMC, but not in recipients that were treated with ALS only (MST = 34 days, in comparison with 29 days for groups that received either a single adult graft or an adult graft with an adult cotransplant). The graft-prolonging effects of an infusion of donor BMC thus appear to potentiate the expression of the cotransplant effect. An understanding of this effect may lead to improved methods of controlling the allograft response to adult tissues in the clinical setting.

Animals↗
PubMed1987

Specific tolerance to canine renal allografts following treatment with fractionated bone marrow and antilymphocyte serum.

These results suggest (1) that ALS + BM fractions can be used to promote tolerance in long-term graft survivors; (2) that the presence of apparent BM cells of donor origin in the allograft in normally functioning kidneys may be related to the mechanism of allograft prolongation, and (3) that some promise of possible specific long-term immunosuppression exists clinically.

Animals↗
PubMed1986

Prolongation of renal allograft survival in antilymphocyte-serum-treated dogs by postoperative injection of density-gradient-fractionated donor bone marrow.

Posttransplant injection of fractionated donor bone marrow cells results in the prolonged survival of mouse skin allografts. In this investigation, we extended the study to the use of donor bone marrow fractionated by density-gradient centrifugation in a larger animal model, canine renal transplantation. Renal allografts were placed in outbred, histoincompatible dogs treated daily with rabbit or horse antilymphocyte serum (ALS) from days -6 to +7 relative to kidney transplantation on day 0. Fresh, unfractionated donor bone marrow (BM) or a bone marrow fraction (BM Fr3) produced by centrifugation in a discontinuous Percoll density gradient was intravenously infused into recipients on days +13 or +14. Alternatively, frozen/thawed (F/Th) BM or BM Fr3 was infused after storage at -80 degrees C for two weeks. BM Fr3 and unfractionated BM significantly (P less than 0.005) prolonged for median allograft function time (MFT) beyond the controls treated only with ALS (46 and 35 days vs. 18 days). The longer MFT with BM Fr3 was achieved with 20-40% of the unfractionated BM cell dose. In addition, BM Fr3-treated dogs exhibited a slower rate of loss of kidney function. F/Th BM was as effective as fresh BM in prolonging graft survival. A reduced mixed lymphocyte response to donor and third-party cells and markedly reduced responsiveness to Con A, PHA, and pokeweed mitogens at 30-45 days posttransplant suggested that animals were nonspecifically immunosuppressed during this period. By 60 days posttransplant, in two dogs treated with BM Fr3, the MLR to third-party cells, but not to donor cells, and the responsiveness to mitogens had returned to pre-ALS treatment values. Thus, treatment with ALS combined with fresh or F/Th BM that has been fractionated is an effective method for the prolongation of kidney allografts in dogs. The development of specific, long-term immunosuppression induced by fractionated bone marrow and success with F/Th BM in this canine renal allograft model suggests that application to human transplantation may be effective with fresh or F/Th BM fractions obtained from living-related or cadaveric donors.

Animals↗