Haploidentical stem cell transplantation(haplo-SCT)achieves superior or at least comparable clinical outcomes to HLA-matched sibling donor transplantation(MSDT)in treating hematological malignancies.To define the unde...Haploidentical stem cell transplantation(haplo-SCT)achieves superior or at least comparable clinical outcomes to HLA-matched sibling donor transplantation(MSDT)in treating hematological malignancies.To define the underlying regulatory dynamics,we analyzed time courses of leukemia burden and immune abundance of haplo-SCT or MSDT from multiple dimension.First,we employed two nonirradiated leukemia mouse models which carried human AML-ETO or MLL-AF9 fusion gene to establish haplo-identical and major histocompatibility(MHC)-matched transplantation models and investigated the immune cell dynamic response during leukemia development in vivo.We found that haplo-matching the MHCs of leukemia cells with recipient mouse T cells prolonged leukemic mice survival and reduced leukemia burden.The stronger graft-versus-leukemia activity in haplo-SCT group mainly induced by decreased apoptosis and increased cytotoxic cytokine secretion including tumor necrosis factor–α,interferon-γ,pore-forming proteins and CD107a secreted by T cells or natural killer cells.Furthermore,we conducted a prospective clinical trial which enrolled 135 patients with t(8;21)acute myeloid leukemia that displayed minimal residual disease before transplantation and underwent either haplo-SCT or MSDT.The results showed that the haplo-SCT slowed the kinetics of the leukemia burden in vivo and reduced the cumulative incidence of relapse compared with MSDT.Ex vivo experiments showed that,1 year after transplantation,cytotoxic T lymphocytes from the haplo-SCT group had higher cytotoxicity than those from the MSDT group during the same period.Our results unraveled the role of immune cells in superior antileukemia effects of haplo-SCT compared with MSDT.展开更多
Background In haploidentical hematopoietic stem cell transplantation （HSCT）, the duration of graft-versus-host disease （GVHD） prophylaxis after modified donor lymphocyte infusion （DLI） was the only risk factor o...Background In haploidentical hematopoietic stem cell transplantation （HSCT）, the duration of graft-versus-host disease （GVHD） prophylaxis after modified donor lymphocyte infusion （DLI） was the only risk factor of DLI-associated grades 3-4 acute GVHD. However, the successful application of modified DLI depended not only on the reduction of severe GVHD, but also on the preservation of graft-versus-leukemia （GVL） effect. Therefore, this study was performed to compare the impact of prophylaxis for 6-8 weeks and prophylaxis for 〈6 weeks on GVL effect after modified DLI in haploidentical HSCT. Methods A total of 103 consecutive patients developing hematological relapse or minimal residual disease （MRD）-positive status after haploidentical HSCT and receiving modified DLI were investigated retrospectively. Fifty-two patients received prophylaxis for 6-8 weeks after modified DLI; the remaining 51 patients received prophylaxis for 〈6 weeks. Results First, compared with prophylaxis for 〈6 weeks, prophylaxis for 6-8 weeks reduced incidence of relapse in total patients （26.6% vs. 69.0%, P 〈0.001）. Besides, prophylaxis for 6-8 weeks also reduced incidence of relapse in 54 patients developing hematological relapse post-transplant （P=0.018） and in 49 patients developing MRD-positive status post-transplant （P 〈0.001）. Second, prophylaxis for 6-8 weeks reduced incidence of acute GVHD （P 〈0.05）, reduced the therapeutic application of immunosuppressive agents （P=0.019）, but increased the incidence of chronic GVHD （P〈0.05）. Third, prophylaxis for 6-8 weeks improved overall survival and disease-free survival in total patients, as well as in patients developing hematological relapse post-transplant and in patients developing MRD-positive status post-transplant （P 〈0.05）. Conclusions In haploidentical HSCT, prophylaxis for 6-8 weeks after modified DLI does not reduce GVL effect, but reduces the incidence of DLI-associated acute GVHD compared with prophylaxis for 〈6 weeks.展开更多
Background We distinguished graft-versus-host disease (GVHD) from graft-versus-leukemia (GVL) effects and to investigate the distribution of T-cell receptor (TCR) Vβ gene repertoire in individuals with leukemia befor...Background We distinguished graft-versus-host disease (GVHD) from graft-versus-leukemia (GVL) effects and to investigate the distribution of T-cell receptor (TCR) Vβ gene repertoire in individuals with leukemia before and after allogeneic hematopoietic stem cell transplantation (allo-HSCT).Methods Peripheral blood mononuclear cells (PBMC) were obtained from 10 normal individuals, 8 donors and 11 patients with leukemia before and after transplantation. Polymerase chain reaction (PCR) amplification of complementarity-determining region 3 (CDR3) of 24 TCR Vβ genes was used to examine serial samples of PBMC. The PCR products were further analyzed by genescan to evaluate clonality of T cells.Results The 24 TCR Vβ gene repertoire displayed highly diverse and polyclonal spectratypes in all normal individuals and 4 of 8 donors. Anoth er 4 donors expressed part of the 24 TCR Vβ subfamily and 1 donor had oligoclonality. The expressions of the 24 TCR Vβ subfamilies were skewed and restric ted in 11 leukemia patients before and after transplantation. Some absences of 24 TCR Vβ subfamily expression were quite similar between the recipients pro-transplantation and related donors. The number of subfamilies expressed increased over time post-transplantation, but the restricted expressions of the subfamily could last 6-30 months after transplantation. All patients with GVHD and some without GVHD exhibited T cell clonal expansion. The expansive T cell clone was distributed in Vβ 2-3, 16-17, 18-19, 21 and Vβ 23 in patients with GVHD and in Vβ 7, 9, 16 and 19 in patients without GVHD. One patient with syngeneic-HSCT (syn-HSCT) had Vβ 15 and 16 T cell expansion after transplantation. One patient displayed Vβ 18 T cell expansion after donor lymphocyte infusion (DLI).Conclusions Normal individuals express the entire 24 TCR Vβ ge ne repertoire and have polyclonal distribution. However, the TCR Vβ gene repertoire is only partially expressed in some donors. The TCR Vβ gene repertoire is restrictedly expressed in a skew fashi展开更多
Objective： The purposes of this study were to assess the efficacy of allogeneic hematopoietic stem cell transplantation （HSCT） for acute leukemia （AL） and analyze the factors affecting the prognosis of these pati...Objective： The purposes of this study were to assess the efficacy of allogeneic hematopoietic stem cell transplantation （HSCT） for acute leukemia （AL） and analyze the factors affecting the prognosis of these patients. Methods： The clinical and follow-up data of 93 AL patients （median age, 30 years） undergoing allogeneic HSCT in Xiangya Hospital over the past 12 years were collected, and the potential factors affecting the efficacy and prognosis of allogeneic HSCT patients were determined. Results： Hematopoietic reconstitution was achieved in 90 patients. At the last follow-up, the incidences of severe acute graft versus host disease （aGvHD） and extensive chronic GvHD （cGvHD） were 14.0% and 20.0%, the 3-year cumulative incidence of transplantation related mortality （TRM） and relapse rate were 16.8%±6.1% and 21.3%±6.7%, and the estimated 3-year overall survival （OS） and disease-free survival （DFS） of the patients were 64.6%±5.4% and 56.5%±5.5%, respectively. Univariate analysis indicated that age older than 40 years, HLA mismatch, and severe lung infection within the first 100 days after transplantation were risk factors for severe aGvHD, age older than 40 years, HLA mismatch, severe lung infection within the first 100 days after transplantation, and severe aGvHD were risk factors for TRM, high-risk AL and lack of cGvHD were risk factors for relapse （all P〈0.05）. Survival estimation showed that HLA mismatch, severe lung infection occurring within the first 100 days post-transplantation, high-risk AL severe aGvHD and lack of cGvHD were risk factors associated with poor prognosis （all P〈0.05）. Further multivariate analyses revealed that severe lung infection within the first 100 days post-transplantation, severe aGvHD and lack of cGvHD were independent risk factors for unfavorable outcomes （all P〈0.05）. Conclusions： Allogeneic HSCT can improve the DFS of AL patients, and severe lung infection within the first 100 days post-transplantation, severe aGvHD and展开更多
Background The role of Wilms＇ tumor 1 protein （WT1）-specific cytotoxic T cells （CTL） in eradicating chronic myeloid leukemia （CML） cells is to be established. The aim of this study was to determine whether WT1 ...Background The role of Wilms＇ tumor 1 protein （WT1）-specific cytotoxic T cells （CTL） in eradicating chronic myeloid leukemia （CML） cells is to be established. The aim of this study was to determine whether WT1 contributed to the graft-versus-leukemia effects （GVLE） for CML following allogeneic hematopoietic stem cell transplantation （HSCT）. Methods High-resolution human leukocyte antigen （HLA） class I genotyping was performed by sequence-specific polymerase chain reaction （PCR）. Fifteen HLA-A~＊2402 patients with CML who underwent allogeneic HSCT were enrolled in this study. We monitored the frequency of WT1-specific CTL by pentamer assay and the molecular minimal residual disease by real-time quantitative PCR.Results A CD8＋ T-cell response to WT1 was observed in 14 of 15 patients after HSCT. The median frequencies of WT1-CTL were 0.54%, 0.62%, 0.81% and 1.28% （%CD8） on days 30, 60, 90 and 180, respectively. The median frequency of WT1-CTL （1.38%） in patients with molecular remission （MoR） was significantly higher than that in those without MoR （0.38%） on day 30, while no significant differences between them were detected on days 60, 90 and 180. The increase of WT1-CTL was associated with a decrease in bcr-abl expression and MoR; and the decrease of WT1-CTL was associated with an increase in bcr-abl expression, suggesting a WT1 -driven GVL effect. WT1-CTL had a predominant effector-memory phenotype （CD45RO＋CD27-CD57＋）.Conclusions The emergence of WT1-CTL with an effector-memory phenotype is associated with GVLE in CML patients after HSCT. This will pave the way for the WT1 vaccines to enhance GVLE after HSCT in CML.展开更多
Objective： To explore whether the graft-versus-leukemia （GVL） effects could be enhanced and acute graft-versus-host disease （aGVHD） could be relieved by syngeneic bone marrow mixed with G-CSF-primed H-2 haploiden...Objective： To explore whether the graft-versus-leukemia （GVL） effects could be enhanced and acute graft-versus-host disease （aGVHD） could be relieved by syngeneic bone marrow mixed with G-CSF-primed H-2 haploidentical marrow grafting. Methods： Female L615 （H-2^k） mice were recipient mice and male （615×BALB/c） F1 （6BF1） （H-2^k×H-2^d） mice were donors respectively. Donor mice were injected subcutaneously with G-CSF daily at 0.01 μg/g for 6 days, and splenocytes were harvested on day 7. A total of 615 mice were loaded with L615 tumor cells and received 8.5 Gy （^60Co γ-ray） irradiation three days later, followed by a mixed bone marrow transplantation （MBMT）. The allo-grafts consisted of a mixture of syngenetic plus G-CSF-mobilized （control diluents） H-2 haploidetical marrow cells. GVL effects were monitored by survival time and survival rate of recipient mice. GVHD was assessed by clinical signs of weight loss, ruffled fur, diarrhea and histological changes of skin, liver and small intestines. AIIogeneic chimerism was detected using cytogenetic analysis. Enzyme-linked immunosorbent assay （ELISA） method was used to detect cytokines （IL-2, IL-4 and IFN-γ）. Fluorescence-activated cell sorting （FACS） analysis was used to detect T-cell phenotype. Results： （1） The mice merely received L615 leukemia cells were all died of leukemia. The L6t5 mice of 3：1 and 4：1 MBMT groups survived longer than those post syngeneic BMT （P 〈 0.01）. （2） The survival time of mice in the G-CSF-treated MBMT groups was longer than that of non-primed MBMT groups （P 〈 0.05）. Administration of G-CSF-treated 6BF1 mice could markedly increase the survival rate of 3：1 and 4：1 MBMT mice （P 〈 0.01） with little or a little GVHD. （3） As the post-transplanted time prolonged, the rates of allogeneic chimerism were decreased. The chimerism rates decreased to zero when the mice died of leukemia relapse. （4） L3T4^＋ cells and relative ratio in both subsets were s展开更多
Aim Allogeneic hematopoietic stem cell transplantation （HSCT） has curable potential for hematopoietic malignancies through graft-versus-leukemia （GVL） effects but is often associated with life-threatening graft-ve...Aim Allogeneic hematopoietic stem cell transplantation （HSCT） has curable potential for hematopoietic malignancies through graft-versus-leukemia （GVL） effects but is often associated with life-threatening graft-versus-host disease （GVHD）. Donor T cells play an important role in the pathological process of GVHD. In this study, to determinate immunoisolation through encapsulating T cells with biomaterials could be a promising approach to atten- uate GVHD. Methods T cells were isolated from spleens of donor C57B1/6 mice by magnetic cell separation and coated by layer-by-layer in chitosan and alginate. BALB/c recipient mice were established by GVHD mode and leukemia mode. Xenogen IVIS imaging system was used for live animal imaging. Donor BMCs and T cell subsets were analyzed by flow cytometry. Results In this study, we successfully encapsulated T cells of mice in multilay- ers of chitosan and alginate. In vitro studies showed that the encapsulation did not change the phenotype of T cells as defined through the following parameters： size, viability, proliferation, antibody binding, cytokine secretion, and cytotoxicity. Mice transplanted with encapsulated allogeneic T cells exhibited less severe acute GVHD and pro- longed survival. The mice showed a lower GVHD score, less liver damage, a smaller CD8/CD4 T cell ratio, and a higher number of donor BM-derived cells following transplantation with encapsulated donor T cells. When this GVHD model was combined with implantation of A20 lymphoma cells, GVL of encapsulated T cells was not com- promised, while GVHD was still suppressed and the mouse survival also prolonged. Conclusion These studies demonstrate that encapsulation of T cells with bio-degradable materials could attenuate the severity of GVHD but re- taine GVL, which presents a novel and potentially safer and effective approach of allogeneic HSCT for future clini- cal application.展开更多
基金supported by grants from the National Key Research and Development Program of China(2017YFA0104500)the Beijing Municipal Science and Technology Commission(Z181100009618032)+2 种基金the National Natural Science Foundation of China(Grant No.81621001,81530046,81770189,81670186,81870141 and 82070185)CAMS Innovation Fund for Medical Sciences(CIFMS)(grant number:2019-I2M-5-034)the Peking University Clinical Scientist Program(BMU2019LCKXJ003).
文摘Haploidentical stem cell transplantation(haplo-SCT)achieves superior or at least comparable clinical outcomes to HLA-matched sibling donor transplantation(MSDT)in treating hematological malignancies.To define the underlying regulatory dynamics,we analyzed time courses of leukemia burden and immune abundance of haplo-SCT or MSDT from multiple dimension.First,we employed two nonirradiated leukemia mouse models which carried human AML-ETO or MLL-AF9 fusion gene to establish haplo-identical and major histocompatibility(MHC)-matched transplantation models and investigated the immune cell dynamic response during leukemia development in vivo.We found that haplo-matching the MHCs of leukemia cells with recipient mouse T cells prolonged leukemic mice survival and reduced leukemia burden.The stronger graft-versus-leukemia activity in haplo-SCT group mainly induced by decreased apoptosis and increased cytotoxic cytokine secretion including tumor necrosis factor–α,interferon-γ,pore-forming proteins and CD107a secreted by T cells or natural killer cells.Furthermore,we conducted a prospective clinical trial which enrolled 135 patients with t(8;21)acute myeloid leukemia that displayed minimal residual disease before transplantation and underwent either haplo-SCT or MSDT.The results showed that the haplo-SCT slowed the kinetics of the leukemia burden in vivo and reduced the cumulative incidence of relapse compared with MSDT.Ex vivo experiments showed that,1 year after transplantation,cytotoxic T lymphocytes from the haplo-SCT group had higher cytotoxicity than those from the MSDT group during the same period.Our results unraveled the role of immune cells in superior antileukemia effects of haplo-SCT compared with MSDT.
文摘Background In haploidentical hematopoietic stem cell transplantation （HSCT）, the duration of graft-versus-host disease （GVHD） prophylaxis after modified donor lymphocyte infusion （DLI） was the only risk factor of DLI-associated grades 3-4 acute GVHD. However, the successful application of modified DLI depended not only on the reduction of severe GVHD, but also on the preservation of graft-versus-leukemia （GVL） effect. Therefore, this study was performed to compare the impact of prophylaxis for 6-8 weeks and prophylaxis for 〈6 weeks on GVL effect after modified DLI in haploidentical HSCT. Methods A total of 103 consecutive patients developing hematological relapse or minimal residual disease （MRD）-positive status after haploidentical HSCT and receiving modified DLI were investigated retrospectively. Fifty-two patients received prophylaxis for 6-8 weeks after modified DLI; the remaining 51 patients received prophylaxis for 〈6 weeks. Results First, compared with prophylaxis for 〈6 weeks, prophylaxis for 6-8 weeks reduced incidence of relapse in total patients （26.6% vs. 69.0%, P 〈0.001）. Besides, prophylaxis for 6-8 weeks also reduced incidence of relapse in 54 patients developing hematological relapse post-transplant （P=0.018） and in 49 patients developing MRD-positive status post-transplant （P 〈0.001）. Second, prophylaxis for 6-8 weeks reduced incidence of acute GVHD （P 〈0.05）, reduced the therapeutic application of immunosuppressive agents （P=0.019）, but increased the incidence of chronic GVHD （P〈0.05）. Third, prophylaxis for 6-8 weeks improved overall survival and disease-free survival in total patients, as well as in patients developing hematological relapse post-transplant and in patients developing MRD-positive status post-transplant （P 〈0.05）. Conclusions In haploidentical HSCT, prophylaxis for 6-8 weeks after modified DLI does not reduce GVL effect, but reduces the incidence of DLI-associated acute GVHD compared with prophylaxis for 〈6 weeks.
基金ThisstudywassupportedbytheNationalNatureScienceFoundationofChina (NO 3 9970 70 6)
文摘Background We distinguished graft-versus-host disease (GVHD) from graft-versus-leukemia (GVL) effects and to investigate the distribution of T-cell receptor (TCR) Vβ gene repertoire in individuals with leukemia before and after allogeneic hematopoietic stem cell transplantation (allo-HSCT).Methods Peripheral blood mononuclear cells (PBMC) were obtained from 10 normal individuals, 8 donors and 11 patients with leukemia before and after transplantation. Polymerase chain reaction (PCR) amplification of complementarity-determining region 3 (CDR3) of 24 TCR Vβ genes was used to examine serial samples of PBMC. The PCR products were further analyzed by genescan to evaluate clonality of T cells.Results The 24 TCR Vβ gene repertoire displayed highly diverse and polyclonal spectratypes in all normal individuals and 4 of 8 donors. Anoth er 4 donors expressed part of the 24 TCR Vβ subfamily and 1 donor had oligoclonality. The expressions of the 24 TCR Vβ subfamilies were skewed and restric ted in 11 leukemia patients before and after transplantation. Some absences of 24 TCR Vβ subfamily expression were quite similar between the recipients pro-transplantation and related donors. The number of subfamilies expressed increased over time post-transplantation, but the restricted expressions of the subfamily could last 6-30 months after transplantation. All patients with GVHD and some without GVHD exhibited T cell clonal expansion. The expansive T cell clone was distributed in Vβ 2-3, 16-17, 18-19, 21 and Vβ 23 in patients with GVHD and in Vβ 7, 9, 16 and 19 in patients without GVHD. One patient with syngeneic-HSCT (syn-HSCT) had Vβ 15 and 16 T cell expansion after transplantation. One patient displayed Vβ 18 T cell expansion after donor lymphocyte infusion (DLI).Conclusions Normal individuals express the entire 24 TCR Vβ ge ne repertoire and have polyclonal distribution. However, the TCR Vβ gene repertoire is only partially expressed in some donors. The TCR Vβ gene repertoire is restrictedly expressed in a skew fashi
文摘Objective： The purposes of this study were to assess the efficacy of allogeneic hematopoietic stem cell transplantation （HSCT） for acute leukemia （AL） and analyze the factors affecting the prognosis of these patients. Methods： The clinical and follow-up data of 93 AL patients （median age, 30 years） undergoing allogeneic HSCT in Xiangya Hospital over the past 12 years were collected, and the potential factors affecting the efficacy and prognosis of allogeneic HSCT patients were determined. Results： Hematopoietic reconstitution was achieved in 90 patients. At the last follow-up, the incidences of severe acute graft versus host disease （aGvHD） and extensive chronic GvHD （cGvHD） were 14.0% and 20.0%, the 3-year cumulative incidence of transplantation related mortality （TRM） and relapse rate were 16.8%±6.1% and 21.3%±6.7%, and the estimated 3-year overall survival （OS） and disease-free survival （DFS） of the patients were 64.6%±5.4% and 56.5%±5.5%, respectively. Univariate analysis indicated that age older than 40 years, HLA mismatch, and severe lung infection within the first 100 days after transplantation were risk factors for severe aGvHD, age older than 40 years, HLA mismatch, severe lung infection within the first 100 days after transplantation, and severe aGvHD were risk factors for TRM, high-risk AL and lack of cGvHD were risk factors for relapse （all P〈0.05）. Survival estimation showed that HLA mismatch, severe lung infection occurring within the first 100 days post-transplantation, high-risk AL severe aGvHD and lack of cGvHD were risk factors associated with poor prognosis （all P〈0.05）. Further multivariate analyses revealed that severe lung infection within the first 100 days post-transplantation, severe aGvHD and lack of cGvHD were independent risk factors for unfavorable outcomes （all P〈0.05）. Conclusions： Allogeneic HSCT can improve the DFS of AL patients, and severe lung infection within the first 100 days post-transplantation, severe aGvHD and
基金This work was supported by the grants from the Outstanding Youth Fund of Natural Science Foundation （No. 30725038）, National 863 Hi-tech Project （No. IRT0702）, Invocation Team Fund （No. 2006AA02Z4A0） and the Ph.D. Programs Foundation of Ministry of Education of China （No. 20060001108）.
文摘Background The role of Wilms＇ tumor 1 protein （WT1）-specific cytotoxic T cells （CTL） in eradicating chronic myeloid leukemia （CML） cells is to be established. The aim of this study was to determine whether WT1 contributed to the graft-versus-leukemia effects （GVLE） for CML following allogeneic hematopoietic stem cell transplantation （HSCT）. Methods High-resolution human leukocyte antigen （HLA） class I genotyping was performed by sequence-specific polymerase chain reaction （PCR）. Fifteen HLA-A~＊2402 patients with CML who underwent allogeneic HSCT were enrolled in this study. We monitored the frequency of WT1-specific CTL by pentamer assay and the molecular minimal residual disease by real-time quantitative PCR.Results A CD8＋ T-cell response to WT1 was observed in 14 of 15 patients after HSCT. The median frequencies of WT1-CTL were 0.54%, 0.62%, 0.81% and 1.28% （%CD8） on days 30, 60, 90 and 180, respectively. The median frequency of WT1-CTL （1.38%） in patients with molecular remission （MoR） was significantly higher than that in those without MoR （0.38%） on day 30, while no significant differences between them were detected on days 60, 90 and 180. The increase of WT1-CTL was associated with a decrease in bcr-abl expression and MoR; and the decrease of WT1-CTL was associated with an increase in bcr-abl expression, suggesting a WT1 -driven GVL effect. WT1-CTL had a predominant effector-memory phenotype （CD45RO＋CD27-CD57＋）.Conclusions The emergence of WT1-CTL with an effector-memory phenotype is associated with GVLE in CML patients after HSCT. This will pave the way for the WT1 vaccines to enhance GVLE after HSCT in CML.
基金"Qing-Lan Project" of Education Department of Jiangsu Province (No. SJS200512).
文摘Objective： To explore whether the graft-versus-leukemia （GVL） effects could be enhanced and acute graft-versus-host disease （aGVHD） could be relieved by syngeneic bone marrow mixed with G-CSF-primed H-2 haploidentical marrow grafting. Methods： Female L615 （H-2^k） mice were recipient mice and male （615×BALB/c） F1 （6BF1） （H-2^k×H-2^d） mice were donors respectively. Donor mice were injected subcutaneously with G-CSF daily at 0.01 μg/g for 6 days, and splenocytes were harvested on day 7. A total of 615 mice were loaded with L615 tumor cells and received 8.5 Gy （^60Co γ-ray） irradiation three days later, followed by a mixed bone marrow transplantation （MBMT）. The allo-grafts consisted of a mixture of syngenetic plus G-CSF-mobilized （control diluents） H-2 haploidetical marrow cells. GVL effects were monitored by survival time and survival rate of recipient mice. GVHD was assessed by clinical signs of weight loss, ruffled fur, diarrhea and histological changes of skin, liver and small intestines. AIIogeneic chimerism was detected using cytogenetic analysis. Enzyme-linked immunosorbent assay （ELISA） method was used to detect cytokines （IL-2, IL-4 and IFN-γ）. Fluorescence-activated cell sorting （FACS） analysis was used to detect T-cell phenotype. Results： （1） The mice merely received L615 leukemia cells were all died of leukemia. The L6t5 mice of 3：1 and 4：1 MBMT groups survived longer than those post syngeneic BMT （P 〈 0.01）. （2） The survival time of mice in the G-CSF-treated MBMT groups was longer than that of non-primed MBMT groups （P 〈 0.05）. Administration of G-CSF-treated 6BF1 mice could markedly increase the survival rate of 3：1 and 4：1 MBMT mice （P 〈 0.01） with little or a little GVHD. （3） As the post-transplanted time prolonged, the rates of allogeneic chimerism were decreased. The chimerism rates decreased to zero when the mice died of leukemia relapse. （4） L3T4^＋ cells and relative ratio in both subsets were s
文摘Aim Allogeneic hematopoietic stem cell transplantation （HSCT） has curable potential for hematopoietic malignancies through graft-versus-leukemia （GVL） effects but is often associated with life-threatening graft-versus-host disease （GVHD）. Donor T cells play an important role in the pathological process of GVHD. In this study, to determinate immunoisolation through encapsulating T cells with biomaterials could be a promising approach to atten- uate GVHD. Methods T cells were isolated from spleens of donor C57B1/6 mice by magnetic cell separation and coated by layer-by-layer in chitosan and alginate. BALB/c recipient mice were established by GVHD mode and leukemia mode. Xenogen IVIS imaging system was used for live animal imaging. Donor BMCs and T cell subsets were analyzed by flow cytometry. Results In this study, we successfully encapsulated T cells of mice in multilay- ers of chitosan and alginate. In vitro studies showed that the encapsulation did not change the phenotype of T cells as defined through the following parameters： size, viability, proliferation, antibody binding, cytokine secretion, and cytotoxicity. Mice transplanted with encapsulated allogeneic T cells exhibited less severe acute GVHD and pro- longed survival. The mice showed a lower GVHD score, less liver damage, a smaller CD8/CD4 T cell ratio, and a higher number of donor BM-derived cells following transplantation with encapsulated donor T cells. When this GVHD model was combined with implantation of A20 lymphoma cells, GVL of encapsulated T cells was not com- promised, while GVHD was still suppressed and the mouse survival also prolonged. Conclusion These studies demonstrate that encapsulation of T cells with bio-degradable materials could attenuate the severity of GVHD but re- taine GVL, which presents a novel and potentially safer and effective approach of allogeneic HSCT for future clini- cal application.
