Prevention of graft-versus-host disease by intra-bone marrow injection of donor T cells

We have recently found that intra-bone marrow-bone marrow transplantation (IBM-BMT) can be used to prevent graft-versus-host disease (GvHD), even when intensive donor lymphocyte infusion (DLI) is carried out. In the present study, in conjunction with IBM-BMT, allogeneic splenic T cells as DLI were also injected into the bone marrow cavity of lethally irradiated (8.5 Gy) recipients. The extent of GvHD was compared with that of recipients that had received allogeneic IBM-BMT plus i.v. injection of allogeneic T cells (intravenous DLI [IV-DLI]). GvHD in recipients treated with allogeneic IBM-BMT plus IBM-DLI was far milder than in those treated with allogeneic IBM-BMT plus IV-DLI. This was confirmed macroscopically and histopathologically. The frequency of regulatory T cells (Tregs) detected as CD4(+)CD25(+) and CD4(+)Foxp3(+) cells was significantly higher in recipients treated with IBM-BMT plus IBM-DLI than in those treated with IBM-BMT plus IV-DLI. Donor-derived helper T (Th) cells polarized to Th2 type in recipients treated with IBM-BMT plus IBM-DLI, whereas Th1 cells were dominant in recipients treated with IBM-BMT plus IV-DLI. Furthermore, the production of transforming growth factor-beta and hepatocyte growth factor from bone marrow stromal cells was enhanced after IBM-DLI. Thus, IBM-BMT plus IBM-DLI seem to preferentially induce Tregs and Th2, resulting in the prevention of GvHD. Disclosure of potential conflicts of interest is found at the end of this article.     

Adult thymus transplantation with allogeneic intra-bone marrow-bone marrow transplantation from same donor induces high thymopoiesis, mild graft-versus-host reaction and strong graft-versus-tumour effects

Although allogeneic bone marrow transplantation (BMT) plus donor lymphocyte infusion (DLI) is performed for solid tumours to enhance graft-versus-tumour (GVT) effects, a graft-versus-host reaction (GVHR) is also elicited. We carried out intra-bone marrow-bone marrow transplantation (IBM-BMT) plus adult thymus transplantation (ATT) from the same donor to supply alloreactive T cells continually. Normal mice treated with IBM-BMT + ATT survived for a long time with high donor-derived thymopoiesis and mild GVHR. The percentage of CD4(+) FoxP3(+) regulatory T cells in the spleen of the mice treated with IBM-BMT + ATT was lower than in normal B6 mice or mice treated with IBM-BMT alone, but higher than in mice treated with IBM-BMT + DLI; the mice treated with IBM-BMT + DLI showed severe GVHR. In tumour-bearing mice, tumour growth was more strongly inhibited by IBM-BMT + ATT than by IBM-BMT alone. Mice treated with IBM-BMT + a high dose of DLI also showed tumour regression comparable to that of mice treated with IBM-BMT + ATT but died early of GVHD. By contrast, mice treated with IBM-BMT + a low dose of DLI showed longer survival but less tumour regression than the mice treated with IBM-BMT + ATT. Histologically, significant numbers of CD8(+) T cells were found to have infiltrated the tumour in the mice treated with IBM-BMT + ATT. The number of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labelling (TUNEL)-positive apoptotic tumour cells also significantly increased in the mice treated with IBM-BMT + ATT. Allogeneic IBM-BMT + ATT thus can induce high thymopoiesis, preserving strong GVT effects without severe GVHR.     

Effects of intrabone marrow-bone marrow transplantation plus adult thymus transplantation on survival of mice bearing leukemia

We recently found that allogeneic intrabone marrow-bone marrow transplantation (IBM-BMT) plus adult thymus transplantation (ATT) from the same donor is effective in mice bearing solid tumors. In the current study, we examined the effects of this strategy on the survival of mice with leukemia. One week after intravenous injection of 1×10(6) leukemic cells (EL-4, H-2(b)) into 8-week-old B6 (H-2(b)) mice, the mice were 8 Gy irradiated and transplanted with 1×10(7) bone marrow cells (BMCs) from 8-week-old BALB/c mice (H-2(d)) by IBM-BMT with or without donor lymphocyte infusion (DLI) or ATT. All the mice without treatment died within 70 days after injection of EL-4. About 40% of those treated with IBM-BMT alone died within 100 days due to tumor relapse. In contrast, those treated with IBM-BMT+DLI or ATT showed the longest survival rate without relapse of leukemia. In addition, the former showed less graft versus host disease (GVHD) than the latter. The mice treated with IBM-BMT+ATT also showed an intermediate percentage of effector memory (EM) and central memory (CM) cells between those treated with BMT alone and those treated with IBM-BMT+DLI. The numbers and functions of T cells increased in those treated with IBM-BMT+ATT with interleukin-2 and interferon-γ production. These results suggest that IBM-BMT+ATT is effective in the treatment of leukemia with strong graft versus leukemia without increased risk of GVHD.     

Prevention of graft-versus-host disease by intrabone marrow injection of donor T cells: involvement of bone marrow stromal cells

We have developed a new and effective method for bone marrow transplantation (BMT): bone marrow cells (BMCs) are injected directly into the bone marrow (BM) cavity of recipient mice. The intrabone marrow injection of BMCs (IBM-BMT) greatly facilitates the engraftment of donor-derived cells, and IBM-BMT can attenuate graft-versus-host reaction (GVHR), in contrast to conventional intravenous BMT (i.v.-BMT). Here, we examine the mechanisms underlying the inhibitory effects of IBM-BMT on GVHR using animal models where GVHR is elicited. Recipient mice (C57BL/6) were irradiated and splenic T cells (as donor lymphocyte infusion: DLI) from major histocompatibility complex-disparate donors (BALB/c) were injected directly into the BM cavity (IBM-DLI) or injected intravenously (i.v.-DLI) along with IBM-BMT. The BM stromal cells (BMSCs) from these recipients were collected and related cytokines were examined. The recipient mice that had been treated with IBM-BMT + i.v.-DLI showed severe graft-versus-host disease (GVHD), in contrast to those treated with IBM-BMT + IBM-DLI. The suppressive activity of BMSCs in this GVHD model was determined. The cultured BMSCs from the recipients treated with IBM-BMT + IBM-DLI suppressed the proliferation of responder T cells remarkably when compared with those from the recipients of IBM-BMT + i.v.-DLI in mixed leucocyte reaction. Furthermore, the level of transforming growth factor-beta and hepatocyte growth factor in cultured BMSCs from IBM-BMT + IBM-DLI increased significantly when compared with those from the recipients of IBM-BMT + i.v.-DLI. Thus, the prevention of GVHD observed in the recipients of IBM-BMT + IBM-DLI was attributable to the increased production of immunosuppressive cytokines from BMSCs after interaction with host reactive T cells (in DLI).     

不同途径的供者淋巴细胞输注对移植物抗宿主病的影响

目的:观察髓腔内供者淋巴细胞输注(IBM-DLI)对异基因小鼠外周造血干细胞移植(allo-PBSCT)后移植物抗宿主病(GVHD)的影响.方法:雌性C57BL/6小鼠为受鼠,接受全身照射(TBI)预处理后,输注雄性BALB/c小鼠来源的经rhG-CSF动员后的外周造血干细胞,分别经尾静脉(IV)和髓腔内进行DLI,建立异基因GVHD模型,观察移植后小鼠的生存状态和GVHD发生情况,应用流式细胞仪检测受鼠体内嵌合体形成和CD4~+CD25~+调节性T细胞(Tregs)比例,酶联免疫吸附实验(ELISA)检测白细胞介素4(IL-4)、γ干扰素(IFN-γ)水平.结果:IBM-DLI组的受鼠GVHD发生比例和严重程度较IV-DLI组明显降低(P＜0.01);移植后第7天各组受鼠骨髓中供鼠来源的细胞比例均在95%以上;与IV-DLI组比较,脾细胞中Tregs比例在IBM-DLI组明显升高(P＜0.01),IBM-DLI组IL-4分泌增多,IFN-γ分泌减少 (P＜0.01).结论:与IV-DLI相比,IBM-DLI有利于减轻GVHD的发生,其机制可能与受鼠体内Tregs细胞比例增高以及Th细胞向Th2细胞分化有关.     

A new strategy for treatment of malignant tumor: intra-bone marrow-bone marrow transplantation plus CD4- donor lymphocyte infusion

Donor lymphocyte infusion (DLI) is clinically used for the treatment of malignant tumors. We have found recently that intra-bone marrow-bone marrow transplantation (IBM-BMT) can be used to treat various autoimmune diseases, even when radiation doses are reduced. In addition, recently we have found that IBM-BMT can prevent not only graft failure but also graft-versus-host disease (GvHD). Based on these findings, we attempted to prevent and treat the progression of a tumor (Meth-A cell line: BALB/c-derived fibrosarcoma) by DLI plus IBM-BMT. When the tumors had grown to approximately 10 x 10 mm, the tumor-bearing BALB/c (H-2(d)) mice were irradiated with 5 Gy, and whole spleen cells from C57BL/6J (B6) (H-2(b)) mice (as DLI) were then intravenously injected into the BALB/c mice. Simultaneously, bone marrow cells (BMCs) from B6 mice were injected directly into the bone marrow cavity of the BALB/c mice (IBM-BMT). The tumors decreased in size, but the mice died of GvHD. However, when CD4(+) T-cell-depleted spleen cells were used for DLI, the recipients showed only mild GvHD and survived longer, due to the slow growth of the tumor. In contrast, when CD8(+) T-cell-depleted spleen cells were used for DLI, the recipients showed more severe GvHD than those injected with whole spleen cells. These results suggest that IBM-BMT plus DLI (the depletion or reduction of a certain cell population like CD4(+) T cells) could be helpful to suppress both GvHD and tumor growth.     

Enhancement of allogeneic hematopoietic stem cell engraftment and prevention of GVHD by intra-bone marrow bone marrow transplantation plus donor lymphocyte infusion

We examined the effect of intra-bone marrow (IBM)-bone marrow transplantation (BMT) in conjunction with donor lymphocyte infusion (DLI) on the engraftment of allogeneic bone marrow cells (BMCs) in mice. Recipients that had received 6 Gy of radiation completely rejected donor BMCs, even when IBM-BMT was carried out. However, when BMCs were IBM injected and donor peripheral blood mononuclear cells (PBMNCs) were simultaneously injected intravenously (DLI), donor cell engraftment was observed 7 days after BMT and complete donor chimerism continued thereafter. It is of interest that the cells of recipient origin did not recover, and that the hematolymphoid cells, including progenitor cells (Lin-/c-kit+ cells) in the recipients, were fully reconstituted with cells of donor origin. The cells in the PBMNCs responsible for the donor BMC engraftment were CD8+. Recipients that had received 6 Gy of radiation, IBM-BMT, and DLI showed only a slight loss of body weight, due to radiation side effects, and had no macroscopic or microscopic symptoms of graft-versus-host disease. These findings suggest that IBM-BMT in conjunction with DLI will be a valuable strategy for allogeneic BMT in humans.     

Leucyl-leucine methyl ester-treated haploidentical donor lymphocyte infusions can mediate graft-versus-leukemia activity with minimal graft-versus-host disease risk.

L-leucyl-L-leucine methyl ester (LLME) prevents GVHD in several animal models by depleting dipeptidyl peptidase I (DPPI)-expressing cytotoxic cellular subsets. However, clinical application has been hampered by difficulties in stem cell engraftment following treatment of donor bone marrow inocula with LLME at the concentrations necessary to purge DPPI-expressing T-cells. Noting that T-cells can mediate graft-versus-leukemia (GVL) responses via both perforin (usually co-expressed in cytotoxic granules with DPPI) and Fas ligand pathways in a murine model, we hypothesized that LLME might be useful for treatment of delayed DLIs for potential GVL activity with a decreased risk of GVHD induction. In regard to the clinical setting, the ex vivo use of LLME for this purpose would circumvent any toxicity issues for donor stem cells, because by that time patients would have already achieved successful engraftment. For our preclinical studies, we used the haploidentical C57BL/6 (B6) (H2b) --> ((B6 x DBA/2)F1 (H(2b/d)) murine model with lethally irradiated hosts that had received transplants of T-cell-depleted bone marrow cells and were challenged with the MMD2-8 myeloid leukemia line (H2d) of DBA/2 origin. A DLI of LLME-treated donor splenocytes, from B6 mice presensitized to recipient alloantigens, was administered in varying doses 14 days post-marrow transplantation, and the potential for both GVHD and GVL activity was assessed. All mice that received any dose of LLME-treated DLI survived indefinitely, without evidence of cachexia nor B-cell hypoplasia, in contrast to the severe and lethal GVHD induced by mock-treated DLI. Histological analysis largely correlated with the symptomatic findings and revealed no GVHD-like lesions in the spleens of LLME-treated DLI recipients, although some mice displayed various degrees of hepatic mononuclear infiltration. Most notably, mice given LLME-treated DLI also experienced DLI dose-dependent increases in survival against the challenge with the MMD2-8 leukemia. LLME-treated splenocytes remained immunocompetent, as these cells could proliferate in response to mitogens and to restimulation with ovalbumin when used as a recall antigen. In conclusion, LLME-treated DLI possesses immune potential and, in particular, GVL activity without inducing clinically evident GVHD.     

Allogeneic intrabone marrow-bone marrow transplantation plus donor lymphocyte infusion suppresses growth of colon cancer cells implanted in skin and liver of rats

We have recently found that allogeneic intrabone marrow-bone marrow transplantation (IBM-BMT) + donor lymphocyte infusion (DLI) using CD4(+) cell-depleted spleen cells (CD4(-) cells) can prevent graft-versus-host disease (GvHD) but suppress tumor growth (Meth A: fibrosarcoma) in mice. In the present study, we show that allogeneic IBM-BMT + DLI using CD4(-) cells also has suppressive effects on the growth of colon cancer cells implanted not only in the skin but also in the liver of rats. First, we examined the effects of allogeneic IBM-BMT + DLI on the subcutaneously inoculated ACL-15 (rat colon cancer cell line). Lethally irradiated Fischer rats (F344 rats) were transplanted with T-cell-depleted bone marrow cells (BMCs) from Brown Norway (BN) rats. Simultaneously, DLI was performed using whole spleen cells (whole cells), CD4(+) cell-depleted spleen cells (CD4(-) cells) or CD8(+) cell-depleted spleen cells (CD8(-) cells) of BN rats. Although allogeneic IBM-BMT + DLI suppressed tumor growth, a considerable number of rats treated with allogeneic IBM-BMT + DLI using whole cells or CD8(-) cells died due to GvHD. In contrast, allogeneic IBM-BMT + DLI using CD4(-) cells also suppressed tumor growth, but there was no GvHD. Based on these findings, we next examined the effects of allogeneic IBM-BMT + DLI using CD4(-) cells on the cancer cells implanted in the liver. Allogeneic IBM-BMT + DLI using CD4(-) cells via the portal vein significantly prolonged the survival. These results suggest that allogeneic IBM-BMT + DLI using CD4(-) cells could become a new strategy for the treatment of solid tumors.     

Photochemical treatment of donor lymphocytes inhibited their ability to facilitate donor engraftment or increase donor chimerism after nonmyeloablative conditioning or establishment of mixed chimerism.

Donor T-cells can provide a graft-versus-leukemia effect and help to promote donor engraftment after allogeneic BMT; however, these benefits can be outweighed by the ability of the cells to induce life-threatening GVHD. Photochemical treatment (PCT) of T-cells with S-59 psoralen and long-wavelength UV-A light can inhibit their proliferative capacity and significantly decrease their ability to induce acute GVHD after allogeneic BMT. PCT donor T-cells have been shown to facilitate donor engraftment in a myeloablative BMT model. In this study, we examined whether donor T-cells subjected to PCT ex vivo could retain the ability to facilitate engraftment or increase donor chimerism after nonmyeloablative BMT or after establishment of mixed hematopoietic chimerism. In a transplantation model in which mice were conditioned for BMT with sublethal (600 cGy) TBI, an infusion of PCT donor T-cells was unable to facilitate engraftment of donor BM. A BMT model was used in which a mixture of allogeneic and syngeneic marrow cells was infused into lethally irradiated recipients for establishment of mixed hematopoietic chimerism. The goal was to determine whether PCT donor splenocytes could increase levels of donor chimerism. Recipients of splenocytes treated with UV-A light only (no S-59 psoralen) and given at the time of BMT or in a donor lymphocyte infusion (DLI) had significantly higher levels of donor chimerism than did recipients of BM only. Although PCT donor splenocytes given at the time of BMT modestly increased donor chimerism, PCT donor splenocytes given in a DLI did not increase donor chimerism. A nonmyeloablative BMT model was employed for determining whether DLI given relatively late after BMT could increase donor chimerism. Recipient mice were conditioned for BMT with a combination of low-dose TBI (50 or 100 cGy) and anti-CD154 (anti-CD40L) monoclonal antibody for achievement of low levels of mixed chimerism. When control mixed chimeras were given a DLI 71 days after BMT, donor chimerism was significantly increased. In contrast, PCT of the donor cells eliminated the ability of the cells to increase donor chimerism after infusion. Together results from these 3 distinct BMT models indicate that PCT of donor T-cells significantly inhibited the ability of the cells to facilitate donor engraftment after nonmyeloablative BMT or to increase donor chimerism in mixed hematopoietic chimeras when the cells were administered in a DLI.     

Facilitation of hematopoietic recovery by bone grafts with intra-bone marrow-bone marrow transplantation

We have previously shown that T cells can acquire donor-type major histocompatibility complex (MHC) restriction and can interact with both donor-type antigen-presenting cells (APCs) and B cells, when adult donor bones are co-grafted with intravenous (IV) injection of bone marrow cells (BMCs) in order to supply donor bone marrow (BM) stromal cells. We have also found that the direct injection of donor BMCs into recipient BM (intra-bone marrow-bone marrow transplantation: IBM-BMT) produces more rapid reconstitution (including T-cell functions) and higher survival rates than IV injection (IV-BMT) even in chimerism-resistant combinations. In the present study, we show that the co-administration of bones from suckling (2-3 days old) donor mice is also effective in the IBM-BMT system. Even when a relatively low number of BMCs were injected into adult (more than 15 weeks old) mice, complete reconstitution was achieved in the mice that had received IBM-BMT+bone grafts, but not in the mice that had received IBM-BMT alone. Most BM and splenic adherent cells obtained from the recipients that had received IBM-BMT+bone grafts were reconstituted by donor-type cells. Both T-cell proliferation and plaque-forming cell assays indicated that the T cells of such mice showed donor-type MHC restriction. Moreover, the analyses of thymic sections using confocal microscopy revealed that donor BM stromal cells had migrated into the thymus. Thus, the co-administration of donor bones has great advantages for allogeneic BMT in adult mice.     

EL9611红白血病小鼠急性GVHD动物模型的建立

目的: 建立EL9611红白血病小鼠急性移植物抗宿主病(GVHD)的动物模型。方法: 同种异基因骨髓移植(allo-BMT)以C57BL/6(H-2^b)鼠为供鼠,BALB/c(H-2^d)为受鼠。设白血病组(n=10)、照射对照组(白血病鼠照射后不进行allo-BMT,n=4)、GVHD组(白血病鼠照射+allo-BMT,n=10)及正常对照组(n=4)。白血病组采用每只BALB/c鼠尾静脉输注2×10⁶个EL9611红白血病细胞建立红白血病动物模型;GVHD组于接种白血病细胞7 d后行总剂量为8.0 Gy的1次性 γ射线全身照射(TBI),照射后5 h内每只小鼠尾静脉输注C57BL/6鼠骨髓细胞2×10⁶个＋脾细胞1×10⁷个,建立EL9611红白血病小鼠的急性GVHD动物模型。观察小鼠体位、皮毛、大便等临床表现,病理检查肝脾、皮肤、小肠、外周血和骨髓,计算生存率。结果: 白血病组生存时间(14.5±2.1) d ,生存时间与GVHD组相比P<0.01,死亡率100％,无自发缓解,死亡时肝脾肿大(肝重2.40 g±0.48 g,脾重0.84 g±0.20 g,与正常对照组比P<0.01),外周血WBC升高 ,病理检查示组织正常结构破坏,白血病细胞浸润。照射对照组生存时间为(9.0±0.7) d,生存时间与GVHD组和正常对照组相比差异显著(P<0.01),死亡率100％,病理检查显示造血衰竭。GVHD组生存时间为(32.0±3.2)d,生存时间与其它各组相比P<0.01,死亡率100％,allo-BMT后第10-13 d出现症状,临床表现和病理检查符合Ⅰ到Ⅱ度GVHD的改变。结论: 采用EL9611红白血病细胞(2×10⁶/鼠)静脉输注的方式可成功建立EL9611红白血病动物模型;接种EL9611红白血病细胞第7 d行TBI +allo-BMT可成功建立EL9611红白血病小鼠的急性GVHD动物模型。     

不同干细胞骨髓腔内输注对移植物抗宿主病和免疫耐受的影响

观察不同来源的造血干细胞经髓腔内输注能否在减轻移植物抗宿主病(GVHD)的同时诱导稳定的免疫耐受。雌性C57BL/6小鼠接受全身照射(TBI)预处理后,输注雄性BABL/c小鼠来源的骨髓细胞或经rhG-CSF动员后的外周造血干细胞,2 d后腹腔注射环磷酰胺(CTX)。观察各组GVHD发生情况,并通过皮肤移植对受者耐受状态进行检测。结果显示,髓腔内骨髓移植组(IBM-BMT)的受鼠无1例发生GVHD,而髓腔内外周造血干细胞移植组(IBM-PBSCT)的受鼠GVHD发生率较尾静脉组(IV)明显减低(P<0.05);IBM-BMT和IBM-PBSCT组受鼠对供鼠皮肤移植物的存活时间均超过120 d,较IV组明显延长(P<0.01)。实验表明髓腔内输注在降低GVHD发生率的同时,有利于稳定的免疫耐受状态的形成。     

T cell repertoire complexity is conserved after LLME treatment of donor lymphocyte infusions.

Slow reconstitution of the T cell repertoire after allogeneic blood or bone marrow stem cell transplantation is a major risk factor for patient mortality. The delivery of immunocompetent T cells as delayed donor lymphocyte infusions (DLIs) is a potential way of counteracting this problem. The development of graft-versus-host disease (GVHD) is a potential complication of this procedure, however. We previously found that in P-->F1 haploidentical murine models, the ex-vivo treatment of donor lymphocytes with L-leucyl-L-leucine methyl ester (LLME) can prevent the onset of GVHD after DLI, likely by inducing cell death in most of the perforin-positive CD8(+) T cells and in a fraction of CD4(+) T cells. Our previous preclinical studies have formed the basis of an ongoing phase I clinical trial in which patients received LLME-treated DLI from their original donor in an attempt to accelerate T cell reconstitution. To understand how this treatment strategy might affect the complexity of the DLI T cell repertoire, we used T cell receptor Vbeta spectratype analysis to evaluate the DLI product pre-LLME and post-LLME treatment. The results indicated that the LLME-treated DLI product exhibited CDR3-size distribution complexities similar to those of its untreated donor sample. In addition, comparisons of the CD4(+) and CD8(+) T cell repertoire from the donor before LLME treatment with that of the recipient post-DLI demonstrated equal complexity for most of the resolvable Vbeta families. Finally, the in vitro proliferative capacity of LLME-treated DLI product in response to allo-stimulation in a one-way mixed lymphocyte reaction was comparable to that of the untreated product.     

慢病毒载体介导的鼠基因工程调节性T细胞对小鼠移植物抗宿主病的作用研究

目的 通过慢病毒载体介导的鼠叉状头螺旋转录因子(Foxp3)基因表达构建鼠基因工程调节性T细胞(Tr),探讨输注基因工程Tr细胞对小鼠异基因骨髓移植后移植物抗宿主病(GVHD)的影响.方法 利用慢病毒载体介导,将鼠Foxp3基因转导入BALB/c小鼠的CD4+CD25-T淋巴细胞,即为基因工程Tr细胞.建立小鼠异基因骨髓移植模型,在移植时联合输注基因工程Tr,通过受鼠移植后生存期、组织病理学改变、炎性细胞因子浓度等指标评价其防治GVHD的作用.并与单纯照射组、移植对照组、空载体对照组相比较.结果 单纯照射组、移植对照组、工程Tr组和空载体对照组小鼠存活时间分别为(8.8±0.6)d、(36.7±2.5)d、(51.6±4.0)d和(34.1±2.3)d,工程Tr组小鼠存活时间明显长于其他各组(P＜0.05).移植对照组及空载体对照组小鼠肝脏、皮肤和小肠病理切片均存在GVHD病理改变,工程Tr组长期存活小鼠的肝脏、皮肤和小肠常规病理切片结构基本正常,未见GVHD病理表现.移植后移植对照组、工程Tr组、空载体对照组受鼠血清IFN-γ、IL-2和TNF-α浓度在21～28 d时达高峰,工程Tr组在21 d时IFN-γ、IL-2和TNF-α浓度高峰较其他两组为低(P＜0.05).结论 小鼠异基因骨髓移植时联合输注基因工程Tr细胞可通过减少受鼠移植后炎性细胞因子的分泌有效减少GVHD的发生,减轻其严重程度.     

Intra-bone marrow injection of donor bone marrow cells suspended in collagen gel retains injected cells in bone marrow, resulting in rapid hemopoietic recovery in mice

We have recently developed an innovative bone marrow transplantation (BMT) method, intra-bone marrow (IBM)-BMT, in which donor bone marrow cells (BMCs) are injected directly into the recipient bone marrow (BM), resulting in the rapid recovery of donor hemopoiesis and permitting a reduction in radiation doses as a pretreatment for BMT. However, even with this IBM injection, some of the injected BMCs were found to enter into circulation. Therefore, we attempted to modify the method to allow the efficient retention of injected BMCs in the donor BM. The BMCs of enhanced green fluorescent protein transgenic mice (C57BL/6 background) were suspended in collagen gel (CG) or phosphate-buffered saline (PBS), and these cells were then injected into the BM of irradiated C57BL/6 mice. The numbers of retained donor cells in the injected BM, the day 12 colony-forming units of spleen (CFU-S) counts, and the reconstitution of donor cells after IBM-BMT were compared between the CG and PBS groups. The number of transplanted cells detected in the injected BM in the CG group was significantly higher than that in the PBS group. We next carried out CFU-S assays. The spleens of mice in the CG group showed heavier spleen weight and considerably higher CFU-S counts than in the PBS group. Excellent reconstitution of donor hemopoietic cells in the CG group was observed in the long term (>100 days). These results suggest that the IBM injection of BMCs suspended in CG is superior to the injection of BMCs suspended in PBS.     

Apoptotic donor leukocytes limit mixed-chimerism induced by CD40-CD154 blockade in allogeneic bone marrow transplantation.

"Mini" allogeneic bone marrow transplants using non-myeloablative conditioning have reduced early treatment-related mortalities, but graft-versus-host disease (GVHD) and graft rejection remain clinical problems. Our preliminary studies indicated that low-dose busulfan conditioning and costimulatory blockade using anti-CD154 monoclonal antibody (mAb) in combination with a pretransplantation "tolerating" dose of bone marrow (BM) cells were sufficient to establish stable mixed-chimerism without GVHD when transplanting moderate doses of T cell depleted (TCD)-BM from major histocompatibility complex (MHC) fully-mismatched donors (Adams AB, Durham MM, Kean L, et al. J Immunol. 2001;167:1103-1111). In this study, donor splenocytes were administered before transplantation as a tolerating cell infusion with a conditioning regimen consisting of low-dose busulfan and anti-CD154 mAb. We compared the ability of viable and apoptotic donor cells of different ex vivo treatments and purified different donor cell populations (CD3(+), CD3(-), CD11b(+), and CD11b(-) splenocytes) to induce tolerance and enhance donor chimerism in a MHC mismatched model of murine bone marrow transplantation. We found that mixed chimerism without GVHD was enhanced by pretransplantation administration of viable allogeneic splenocytes and diminished in mice with prior exposure to apoptotic/necrotic donor splenocytes. CD11b(+)-enriched splenocytes more potently enhanced donor chimerism compared to unfractionated splenocytes or other splenocyte subsets. Mixed lymphocyte cultures demonstrated that apoptotic stimulators overcame the immune-tolerating activity of anti-CD154 mAb and led to increased interferon gamma and tumor necrosis factor alpha synthesis, increased proliferation of responder T cells, and decreased production of interleukin-10. In conclusion, viable donor splenocytes administered before transplantation in combination with costimulatory blockade induced tolerance and enhanced donor chimerism, whereas pretransplantation administration of apoptotic/necrotic donor cells led to host T cell activation and decreased overall donor engraftment.     

T cell and B Cell immunity can be reconstituted with mismatched hematopoietic stem cell transplantation without alkylator therapy in artemis-deficient mice using anti-natural killer cell antibody and photochemically treated sensitized donor T cells

Children with Artemis-deficient T(-)B(-)NK(+) severe combined immunodeficiency are at high risk for graft rejection from natural killer (NK) cells and toxicity from increased sensitivity to the alkylating agents used in mismatched hematopoietic stem cell transplantation (HSCT). We evaluated the use of a nonalkylating agent regimen before HSCT in Artemis-deficient (mArt(-/-)) C57Bl/6 (B6) mice to open marrow niches and achieve long-term multilineage engraftment with full T cell and B cell immune reconstitution. We found that partial depletion of both recipient NK cells using anti-NK1.1 monoclonal antibody and donor T cells sensitized to recipient splenocytes was necessary. BALB/c-sensitized T cells (STCs) were photochemically treated (PCT) with psoralen and UVA light to inhibit proliferation, reduce the risk of graft-versus-host disease (GVHD), and target host hematopoietic stem cells (HSCs). A dose of 4 × 10(5) PCT STCs coinjected with 1 × 10(5) lineage-depleted c-kit(+) BALB/c HSCs resulted in 43.9% ± 3.3% CD4(+) and 10.9% ± 1.2% CD8(+) donor T cells in blood, 29% ± 7.8% and 21.7% ± 4.0 donor B220(+) IgM(+) in spleen and bone marrow, and 15.0% ± 3.6% donor Gran-1(+) cells in bone marrow at 6 months post-HSCT versus 0.02% ± 0.01%, 0.13% ± 0.10%, 0.53% ± 0.16%, 0.49% ± 0.09%, and 0.20% ± 0.06%, respectively, in controls who did not receive PCT STCs. We found that STCs target host HSCs and that PCT STCs are detectable only up to 24 hours after infusion, in contrast to non-photochemically treated STCs, which proliferate resulting in fatal GVHD. Increased mortality in the groups receiving 4-6 × 10(5) PCT STCs was associated with evidence of GVHD, particularly in the recipients of 6 × 10(5) cells. These results demonstrate that blocking NK cell-mediated resistance and making niches in bone marrow are both essential to achieving multilineage engraftment of mismatched donor cells and T cell and B cell reconstitution, even though GVHD is not completely eliminated.     

Graft-facilitating doses of ex vivo activated gammadelta T cells do not cause lethal murine graft-vs.-host disease.

The purpose of this study was to examine the ability of gamma(delta) T cells to cause graft-vs.-host disease (GVHD) after allogeneic bone marrow transplantation (BMT) and to determine whether these cells offered any therapeutic advantages relative to alphabeta T cells. Due to the paucity of naive gamma(delta) T cells in mice and humans, gamma(delta), T cells (obtained from alpha(beta) T cell-deficient murine donors) were ex vivo activated and expanded in interleukin (IL)-2 so as to achieve sufficient cell numbers and to serve as a more clinically feasible strategy. After transplantation into lethally irradiated hosts, donor gamma(delta) T cells were detected in target organs of GVHD such as the spleen and intestines 2 weeks after BMT and constituted the primary T cell subpopulation. Large doses (150 x 10(6)) of activated gamma(delta) T cells, which we have previously shown capable of facilitating engraftment in MHC-disparate recipients, failed to cause fatal GVHD in lethally irradiated recipients of MHC-incompatible donor marrow grafts (C57BL/6 [H-2b]-->B10.BR [H-2k] and C57BL/6 [H-2b]-B6D2F1[H-2b/d]). The absence of GVHD was confirmed by histologic analysis of target organs, splenic B cell reconstitution, and appropriate negative selection in the thymus, that were all comparable to those observed in mice transplanted with T cell-depleted BM only. While early splenic reconstitution was attributable to donor gamma(delta) T cells, analysis of durably engrafted chimeras 2 months posttransplant revealed that the vast majority of donor splenic T cells expressed the alpha(beta) T cell receptor. The results of secondary adoptive transfer assays showed that these cells were tolerant of recipient alloantigens in vivo, demonstrating that gamma(delta) T cells did not prevent the subsequent development of donor anti-host tolerance in BM-derived alpha(beta) T cells. When comparatively evaluated, the minimal number of naive alpha(beta) T cells necessary for donor engraftment caused significantly more fatal GVHD than the corresponding minimal dose of activated gamma(delta) T cells and thus had a superior therapeutic index. These studies indicate that doses of activated gamma(delta) T cells that are able to promote alloengraftment do not cause lethal GVHD in mice transplanted with MHC-incompatible marrow grafts.     

Donor natural killer (NK1.1+) cells do not play a role in the suppression of GVHD or in the mediation of GVL reactions after DLI.

Donor regulatory T cells (CD3+ alphabetaT-cell receptor [TCR]+) derived from the repopulating host thymus have been shown to be primarily responsible for suppression of GVHD following DLI therapy in murine BMT models. However, natural killer (NK) T cells also have regulatory properties, and a role for NK T cells in suppression of GVH reactivity has not been completely excluded. NK cells may also contribute to the graft-versus-leukemia (GVL) effect associated with DLI therapy. In this study, we used a murine BMT model (C57BL/6 into AKR) to study whether depletion of donor NK cells had any impact on the suppression of GVH reactivity after DLI or on the DLI-induced GVL effect against acute T-cell leukemia. Depletion of donor NK cells was accomplished in vivo by giving DLI-treated bone marrow chimeras multiple injections of anti-NK1.1 monoclonal antibody (MoAb). The chimeras treated with anti-NK1.1 MoAb had significantly fewer splenic NK1.1 cells than nontreated chimeras, and splenocytes from anti-NK1.1-treated mice were deficient in the ability to generate lymphokine-activated lytic activity. Results presented here showed that NK-cell depletion had no effect on the suppression of GVH reactivity after DLI. When DLI-treated chimeras were challenged with an acute T-cell leukemia, NK-cell depletion had no discernible effect on GVL reactivity. These preclinical data suggest that donor NK cells do not have a significant role in the suppression of GVHD after DLI or in the mediation of GVL reactivity induced by DLI.