Anti-CD25 monoclonal antibody (basiliximab) for prevention of graft-versus-host disease after haploidentical bone marrow transplantation for hematological malignancies.

Haploidentical donors are available for most patients who need allografts but do not have matched donors. However, GVHD, rejection, delayed immune reconstitution, and infections have been significant barriers. We designed a haploidentical BMT protocol focusing on prevention of GVHD and rejection. A total of 53 leukemic patients underwent haploidentical G-CSF-primed BMT without ex vivo T-cell depletion. GVHD prophylaxis consisted of antithymocyte globulin, cyclosporine, methotrexate, and mycophenolate mofetil. In all, 38 patients (the CD25 group) received additional anti-CD25 monoclonal antibody basiliximab. The results were compared to 15 patients who did not receive basiliximab. All patients achieved trilineage engraftment with full-donor chimerism. The incidence of acute II-IV GVHD was 11% in the CD25 group vs 33% in the control group (P=0.046). The overall incidence of extensive chronic GVHD was 15%. T, B, and NK cells recovered within 12 months post transplant. The disease-free survival at 2 years was 53% with a median follow-up of 31 months. In conclusion, G-CSF primed haploidentical BMT along with sequential immunosuppressive agents as described here deserves further study.

Delaying transplantation after total body irradiation is a simple and effective way to reduce acute graft-versus-host disease mortality after major H2 incompatible transplantation.

BACKGROUND: We have previously reported that delaying histoincompatible transplantation after total body irradiation (TBI) conditioning markedly decreased the mortality of acute graft-versus-host disease (GVHD) in severe combined immunodeficiency mice. However, it was not clear whether the delayed transplantation would affect the final engraftment and acute GVHD mortality in normal hosts. METHODS: BALB/c mice (H2d) were lethally irradiated with 8.5 Gy TBI and transplanted with C57BL/6 (H2d) bone marrow plus spleen cells on the same day (TBI+day 0) or 4 days after TBI conditioning (TBI+day 4). RESULTS: We again demonstrated that delaying transplantation by 4 days after TBI conditioning markedly reduced acute GVHD mortality in normal hosts after major histoincompatible transplantation. The survival rates were 66% in TBI+day 4 vs. 0% in TBI+day 0 allogeneic transplanted animals by day +60 (P<0.001). Further analysis demonstrated that the 4-day rest between the TBI and allogeneic transplantation broke the interaction of cell/inflammatory tumor necrosis factor-alpha, interleukin (IL)-1beta, and IL-6 cytokine reactions stimulated by TBI and incompatible transplantation. Flow cytometry revealed 97% donor cells in host marrow by 2 weeks in TBI+day 0 transplantation versus 57% in TBI+day 4 transplantation. There was no difference in percentage of donor CD3+ T-cell engraftment between the TBI+day 0 and TBI+day 4 allogeneic transplanted animals. In TBI+day 4 transplantation, the percentage of donor cells in host marrow steadily increased to 74% by day +60 and 93% by day +100. CONCLUSIONS: This 2- to 3-month early mixed chimerism in TBI+day 4 transplanted animals might be related to lower levels of tumor necrosis factor-alpha and IL-6 both of which have been shown to stimulate lymphohematopoiesis and was associated with lower acute GVHD mortality. The data again demonstrated in immunologically normal BALB/c mice that delaying allogeneic transplantation after TBI is a simple and effective way to reduce acute GVHD mortality, achieve satisfactory engraftment and significantly increase overall survival.

The effect of human IL-2-activated natural killer and T cells on graft-versus-host disease and graft-versus-leukemia in SCID mice bearing human leukemic cells.

We have previously reported that xenogeneic lethal acute graft-versus-host disease (GVHD) was induced by transplantation of a mixture of human IL-2 activated natural killer (NK) and T cells into SCID mice conditioned with 4 Gy total-body irradiation (TBI), but not by IL-2-activated pure human T cells or NK cells. TBI and transplantation of the mixture of activated cells were both required to produce the lethal effect. We now report the effect of human IL-2 activated NK, T, or NK+T effector cells on the development of acute and chronic GVHD and GVL in SCID mice bearing human leukemic cells. Ten days after being inoculated i.v. with 2 x 10(7) human U-937 or K-562 leukemic cells, SCID mice, hereafter termed hu-leukemic mice, were radiated with 4 Gy TBI and transplanted i.v. with 5 x 10(7) human IL-2-activated NK, T, or NK+T effector cells. Hu-leukemic control mice received neither TBI nor effector cell transplantation. Acute GVHD-positive control SCID mice were transplanted with 5 x 10(7) H-2-incompatible C57Bl/6 splenocytes following 4 Gy TBI. The mice were observed for signs of GVHD and leukemia for 90 days. Twenty of 20 non-effector cell-transplanted control hu-leukemic mice developed signs related to leukemia and died with leukemic infiltration in the brain, liver, kidney, and lung 50-65 days after inoculation. Flow cytometry (FC) demonstrated 21-89% human leukemic cell infiltration in the bone marrow. Fourteen of 14 hu-leukemic mice transplanted with NK+T effector cells did not develop signs of advanced leukemia but died within 17 days of acute GVHD. FC demonstrated no human leukemic cells in their marrow. Twelve of 15 and 18 of 25 hu-leukemic mice transplanted with either NK or T cells survived 90 days without any evidence of symptomatic leukemia (P < 0.01 compared with non-effector cell-transplanted groups). NK-transplanted hu-leukemic animals experienced mild-to-moderate acute GVHD during the first 10-20 days posttransplantation, but gradually recovered and did not develop chronic GVHD. Hu-leukemic animals transplanted with T effector cells manifested no signs of leukemia or acute GVHD but chronic GVHD skin lesions appeared 80-90 days after transplantation. We conclude that acute GVHD, chronic GVHD, and GVL are associated but separable phenomena.

G-CSF-primed haploidentical marrow transplantation without ex vivo T cell depletion: an excellent alternative for high-risk leukemia.

Based on our encouraging results of G-CSF-primed HLA-matched related marrow transplants for high-risk leukemia, we extended the study from matched related to haploidentical transplants using G-CSF primed marrow and sequential immunosuppressants to prevent both graft-versus-host disease (GVHD) and host-versus-graft rejection (HVGR). Fifteen high-risk leukemia patients, who needed urgent transplantation but lacked an HLA-matched donor, underwent G-CSF-primed haploidentical marrow transplantation without ex vivo T cell depletion. Donors were given G-CSF (Lenograstim) at 3-4 microg/kg/day for 7 days prior to marrow harvest. GVHD and HVGR prophylaxis were combined in the sequential usage of cyclosporin A, methotrexate, anti-thymocyte globulin and mycophenolate mofetil. All patients established sustained trilineage engraftment at a median of 19 days and 21 days for neutrophil and platelets respectively. G-CSF priming significantly increased CD34(+) and CFU-GM cells, reduced total lymphocytes and reversed the CD4(+)/CD8(+) ratio in the donor marrow. The incidence of grade II-IV acute GVHD was 33.3%. Nine patients survived more than a year with a Karnofsky performance status of 100%. Estimated overall disease-free survival at 2 years was 60 +/- 7%. In conclusion, using G-CSF priming marrow grafts along with sequential immunosuppressants provided an excellent alternative for the treatment of high-risk hematological malignancy in patients who lack matched donors.

Stimulation of synthesis de novo of NAD(+)-dependent 15-hydroxyprostaglandin dehydrogenase in human promyelocytic leukaemia (HL-60) cells by phorbol ester.

Human promyelocytic leukaemia (HL-60) cells were employed to study the induction of NAD(+)-dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH), the key enzyme in controlling prostaglandin inactivation. Phorbol 12-myristate 13-acetate (PMA) stimulated 15-PGDH activity in a time- and concentration-dependent manner. Dimethyl sulphoxide (DMSO) also stimulated the enzyme activity, although a much delayed stimulation was observed. Western blot studies indicated that PMA increased significantly a 28 kDa immunoreactive protein characteristic of 15-PGDH. L-[35S]Methionine labelling of the PMA-treated cells showed a similar enhancement over the control cells. These studies indicate that PMA induced synthesis of 15-PGDH. Stimulation of 15-PGDH activity by PMA or DMSO appears to be mediated by protein kinase C activation, since an inactive analogue of PMA failed to induce the effect, and both staurosporine and H-7 blocked the stimulation. Stimulation by PMA was optimal at 10 nM and less effective at higher concentrations. Western blot studies indicated that a similar, if not greater, amount of enzyme protein was induced at high concentrations of PMA, suggesting that enzyme inactivation might be occurring. Possible enzyme inactivation by protein kinase C activation was further examined by incubating DMSO-treated cells with a high concentration of PMA (50 nM). Time-dependent inactivation of 15-PGDH within the first 1 h was observed and this inactivation was partially blocked by staurosporine and H-7. Pulse-chase experiments indicated that 15-PGDH had a rapid turnover rate (t 1/2 = 47 min), and PMA shortened the half-life of the enzyme (t 1/2 = 33 min), suggesting that PMA might have an additional effect on 15-PGDH degradation. The rapid turnover of 15-PGDH indicates that the enzyme activity depends on continued enzyme synthesis, and this could be susceptible to hormone and drug control mechanisms.

Regulation of synthesis and activity of NAD(+)-dependent 15-hydroxy-prostaglandin dehydrogenase (15-PGDH) by dexamethasone and phorbol ester in human erythroleukemia (HEL) cells.

Dexamethasone stimulated 15-PGDH activity in HEL cells in a time and concentration dependent manner. Increase in 15-PGDH activity by dexamethasone was found to be accompanied by an increase in enzyme synthesis as revealed by Western blot and [35S]methionine labeling studies. In addition to dexamethasone, other anti-inflammatory steroids also increased 15-PGDH activity in the order of their glucocorticoid activity. Among sex steroids only progesterone increased significantly 15-PGDH activity. 12-0-Tetradecanoylphorbol-13-acetate (TPA) also induced the synthesis of 15-PGDH but inhibited the enzyme activity. It appears that TPA caused a time dependent inactivation of 15-PGDH by a protein kinase C mediated mechanism.

Effect of total body irradiation, busulfan-cyclophosphamide, or cyclophosphamide conditioning on inflammatory cytokine release and development of acute and chronic graft-versus-host disease in H-2-incompatible transplanted SCID mice.

In a previous study, we found that total body irradiation (TBI) was essential to induce acute graft-versus-host disease (GVHD) after allogeneic H-2-incompatible splenocyte (SP) transplantation in SCID mice. SCID mice (H-2d) conditioned with cyclophosphamide and transplanted intravenously (IV) with 5 x 10(7) C57BL/6 (H-2b) SP developed chronic GVHD within 3 months posttransplant without any evidence of preceding acute GVHD. In this study, SCID mice were conditioned with 4 Gy TBI or non-TBI regimens, either BuCy2 (busulfan 4 mg/kg/d + cyclophosphamide 100 mg/kg/d for 2 days) or Cy5 (cyclophosphamide 100 mg/kg/d for 5 days), and then transplanted IV with 5 x 10(7) SP. The TBI-conditioned mice were further divided into tree transplant groups: (1) TBI and SP administered the same day (TBI + D0 SP), (2) SP administered 4 days post-TBI (TBI + D4 SP), and (3) SP administered 7 days post-TBI (TBI + D7 SP). The severity of GVHD was compared among these groups by clinical and histologic grading. Twenty-eight of 28 mice treated with TBI + D0 SP died of acute GVHD, with overwhelming diarrhea by day 15 posttransplantation. Sixteen mice treated with either TBI + D4 SP or TBI + D7 SP developed acute GVHD, but none of them died of this disorder during 30 days posttransplantation. The mice conditioned with non-TBI regimens developed chronic GVHD within 3 months without showing any detectable signs of acute GVHD. Serum and in situ colonic cytokines were determined by enzyme-linked immunosorbent assay and immunohistology respectively. TBI itself significantly increased both serum and colonic tumor necrosis factor-alpha (TNF-alpha), interleukin-1 alpha (IL-1 alpha), and IL-6 when compared with non-TBI regimens and normal controls. TNF-alpha appeared in the serum and colon 4 hours post-TBI and peaked in 24 hours, followed by increasing IL-1 alpha and then IL-6 levels. TNF-alpha and IL-1 alpha decreased rapidly within 3 to 5 days post-TBI if no allogeneic cells were transplanted. Histoincompatible transplantation augmented cytokine release, which remained elevated on day 10 in these animals. Mice treated with TBI + D0 SP developed the most severe acute GVHD and had the highest levels of TNF-alpha, IL-1 alpha, and IL-6. The BuCy2-conditioned mice had the lowest cytokine levels and developed no acute GVHD. When the mice transplanted with TBI + D0 SP were treated immediately with recombinant soluble human TNF receptor (rhuTNFR:Fc) 100 micrograms/d intraperitoneally and for the subsequent 15 days acute GVHD mortality was significantly reduced from 100% to 50% (P < .001).(ABSTRACT TRUNCATED AT 400 WORDS)

The effect of G-CSF-stimulated donor marrow on engraftment and incidence of graft-versus-host disease in allogeneic bone marrow transplantation.

Graft-versus-host disease (GVHD) and infection are major obstacles to successful allogeneic bone marrow transplantation (allo-BMT). In an attempt to improve the results of HLA-identical sibling BMT, we investigated the effect of accelerating hemopoietic reconstitution and reducing acute GVHD (aGVHD) in allo-BMT receiving G-CSF-stimulated donor marrow and the preliminary biological mechanism. The donors of 30 patients (study group) with leukemia were given G-CSF 3-4 microg/kg/d for 7 doses prior to marrow harvest. The results of subsequent engraftment in the recipients were compared with those of 18 patients without G-CSF (control group). Five donors themselves were studied to assess the effects of G-CSF on the hematopoietic progenitor cells and lymphocyte subsets in the bone marrow (BM). We observed that the stimulated BM yielded higher numbers of nucleated cells as well as CFU-GM and CD34+ cells (p<0.01), and that hemopoietic reconstitution was accelerated. The median number of days of granulocyte count exceeding 0.5x10(9)/L and platelet count exceeding 20x10(9)/L was 16 (range 10-23 d) and 18.5 (range 13-31 d), respectively (control group: median 22 d, range 13-29 d and median 23 d, range 17-34 d; p=0.001). The incidence of grade II-IV severe aGVHD was very low, with only 1 case (3.3%) with acute grade II aGVHD limited to the skin in the study group. Five of 18 patients in the control group manifested grade II-IV severe aGVHD (27.8%, p=0.02). The number of T-lymphocyte subsets in the harvested BM using G-CSF stimulation was changed. In the G-CSF-stimulated marrow group, CD4+ decreased and CD8+ increased significantly (p=0.02). The changes of progenitor cells and T-lymphocyte subsets in donors' BM from pre- and post-G-CSF stimulation showed that the percentage of CD4+ reduced (p=0.04) and that of CD8+ increased (p=0.06), while that of CD34+ also increased (p=0.002). The incidence of chronic GVHD and relapse had no significant difference between both groups. These results indicate that allo-BMT in BM G-CSF priming can accelerate engraftment and minimize the incidence of severe aGVHD. There is a trend in favor of improved transplantation-related mortality.

A model of human anti-T-cell monoclonal antibody therapy in SCID mice engrafted with human peripheral blood lymphocytes.

A chimeric severe combined immunodeficient mouse engrafted with human peripheral blood (hu-PBL-SCID) model has been developed to test anti-T-cell monoclonal antibody (mAb) effects on systemic symptoms of the host and the survival of human skin grafts. To obtain consistent engraftment without lethal acute graft-versus-host disease (GVHD), SCID mice were pretreated with a combination of total body irradiation (2.5 Gy, day 0) and anti-asialo GM1 (anti-mouse natural killer cell) antiserum (50 micrograms i.p., day 3) before the intraperitoneal injection of 40-50 X 10(6) human PBL on day 4. With this protocol, the engraftment rate was 82% with 5-98% human CD45-positive cells in the peripheral blood. Mortality at 30 days was 0% in the mice bearing 5-50% human cells compared with 70% in those with more than 50%. Using hu-PBL-SCID mice with 5-50% human cells in their peripheral blood, we demonstrated the following results: 1) Human T cells isolated from these mice proliferated in response to immobilized OKT3 stimulation in vitro. 2) Hu-PBL-SCID mice but not normal SCID mice were able to reject human skin grafts in vivo 16-21 days after grafting. 3) Both OKT3 (anti-human CD3 mAb) and T10B9 (anti-human alpha beta T-cell receptor mAb) treatment prevented human skin graft rejection in hu-PBL-SCID mice. 4) OKT3 but not T10B9 induced first dose reactions characterized by hypothermia and hypoactivity which were consistently observed within 90 min of intravenous injection into hu-PBL-SCID mice. 5) Human cytokines were detected in the serum of the hu-PBL-SCID mice treated with anti-T-cell mAbs. The close similarity of these responses to human clinical mAb immunosuppressive therapy suggests that the hu-PBL-SCID mouse model may be an excellent tool for investigating the immunosuppression, side effects, and mechanism of action of agents that are specific for human and higher apes and not reactive with lower animals.