Engraftment of discordant xenogeneic swine bone marrow cells in immunodeficient mice

Abstract: We have recently demonstrated that swine bone marrow cells (BMC) can engraft in C.B-17 scid mice. While engraftment is enhanced by providing donor-specific porcine cytokines, the level of swine hematopoiesis declines between 3 and 6 weeks post-transplant. In the present study, the utility of several strains of immunodeficient mice as recipients of swine hematopoietic cells has been determined by comparing levels of swine bone marrow engraftment at 3 weeks after bone marrow transplant. Irradiated recipients were injected with lxlO8 swine BMC and were treated daily with porcine cytokines. The presence of swine cells in BMT recipients was detected by flow cytometry and marrow colony-forming assays. Recombination activating gene-1 (RAG-1)-deficient mice were not permissive for the engraftment of swine BMC, even with administration of increased doses of whole body irradiation, or with depleting anti-NK cell antibody. In contrast, NOD-scid mice showed improved swine BMC engraftment compared to C.B-17 scid mice. Levels of swine class I+, myeloid, and CD2+ cells in bone marrow, spleen, and peripheral blood, and the number of porcine myeloid progenitor cells was significantly higher in NOD-scid recipients than in simultaneous C.B-17 scid recipients. In addition, the sera from C.B-17 scid mice markedly inhibited the proliferation of swine BMC in vitro. A weaker inhibitory effect was also mediated by sera from RAG-1-deficient mice, but not by sera from NOD-scid mice. Together, our results indicate that multiple host elements resist xenogeneic hematopoietic engraftment and function, some of which are clearly independent of host T, B, or NK cells. Understanding the basis for the advantage of NODscid mice as recipients of discordant xenogeneic porcine BMC will help to identify these elements.     

Use of G‐CSF‐stimulated marrow in allogeneic hematopoietic stem cell transplantation settings: a comprehensive review

Chang Y‐J, Huang X‐J. Use of G‐CSF‐stimulated marrow in allogeneic hematopoietic stem cell transplantation settings: a comprehensive review.
Clin Transplant 2011: 25: 13–23. © 2010 John Wiley & Sons A/S. Abstract: In recent years, several researchers have unraveled the previously unrecognized effects of granulocyte colony‐stimulating factor (G‐CSF) on hematopoiesis and the immune cell functions of bone marrow in healthy donors. In human leukocyte antigen‐matched or haploidentical transplant settings, available data have established the safety of using G‐CSF‐stimulated bone marrow grafts, as well as the ability of this source to produce rapid and sustained engraftment. Interestingly, G‐CSF‐primed bone marrow transplants could capture the advantages of blood stem cell transplants, without the increased risk of chronic graft‐versus‐host disease that is associated with blood stem cell transplants. This review summarizes the growing body of evidence that supports the use of G‐CSF‐stimulated bone marrow grafts as an alternative stem cell source in allogeneic hematopoietic stem cell transplantation.     

Rat hepatocyte engraftment in severe combined immunodeficient x beige mice using mouse-specific anti-fas antibody

BACKGROUND: Hepatocyte transplantation holds promise as a treatment for acute and chronic liver failure; however, robust model systems needed to study xenogeneic hepatocyte transfer are lacking. Severe combined immunodeficient x beige (SCID/bg) hybrid mice readily accept foreign tissue. Repopulation of C.B-17 SCID/bg mouse liver with rat hepatocytes was studied following induction of mouse hepatocyte apoptosis using an anti-mouse agonistic fas monoclonal antibody (Jo2 mAb) that does not engage xenogeneic fas. METHODS: SCID/bg mice were transplanted with 1 x 10(6) fresh adult rat hepatocytes intrasplenically and treated with various doses, routes and frequencies of Jo2 mAb. Rat cell repopulation was characterized by quantitative immunofluorescent antibody (q-IFA) staining specific for rat dipeptidyl peptidase type IV (DPP-IV) and leucine amino peptidase, amplification of rat genomic DNA using polymerase chain reaction and histopathological and serum biochemistry analyses. RESULTS: Analysis of liver sections from mice treated twice weekly for 12 weeks with 0.4 mg/kg Jo2 mAb intraperitoneally consistently demonstrated >50% rat hepatocytes in the parenchymal mass by q-IFA. Rat hepatocyte engraftment protected mice from Jo2 mAb-mediated liver hemorrhage and hepatocyte apoptosis. Serum liver enzyme levels did not increase in Jo2 mAb-treated mice that were highly engrafted with rat hepatocytes, in contrast to matched non-engrafted mice. At 12 weeks post-engraftment, minimal fibrosis and inflammation were apparent and liver architecture had returned to near normal. Jo2 mAb did not induce histopathological abnormalities in other tissues known to express fas antigen (i.e. heart, lung). CONCLUSIONS: This novel model represents a simple and robust system of xenogeneic hepatocyte transplantation that could be applied to studies of liver biology, regeneration and hepatocyte transplantation.     

粒细胞集落刺激因子联合携带肝细胞生长因子基因的BMSCs移植对心肌梗死大鼠血管重建的影响

目的研究粒细胞集落刺激因子(granulocyte colony stimulating factor,G-CSF)联合携带肝细胞生长因子(hepatocyte growth factor,HGF)基因的BMSCs移植对心肌梗死大鼠血管重建的影响,初步探讨作用机制。方法取3周龄雄性SD大鼠骨髓分离培养BMSCs,取第3代BMSCs以携带HGF基因的5型复制缺陷型腺病毒(Ad-HGF)感染。成年雄性SD大鼠44只,体重200～250 g,结扎左冠状动脉建立心肌梗死模型。造模4周后心脏超声检查,以左室短轴缩短率(shorting fraction,FS)<30%作为造模成功标准。取其中12只大鼠,于梗死心肌边缘注射0.1 mL Ad-HGF感染的BMSCs(5×107个/mL),2、7、14 d后用Western blot方法检测大鼠体内HGF蛋白的表达。将其余32只大鼠随机分为4组,每组8只:对照组注射0.1 mL生理盐水;G-CSF组注射0.1 mL生理盐水并于腹腔注射G-CSF 100μg(/kg.d)共5 d;HGF组注射0.1 mL Ad-HGF感染的BMSCs(5×107个/mL);联合治疗组注射0.1 mL Ad-HGF感染的BMSCs(5×107个/mL)并于腹腔注射G-CSF 100μg/(kg.d)共5 d。细胞移植后2周,行心功能和血流动力学检测,然后处死大鼠取心肌组织行免疫荧光双染后激光共聚焦显微镜下评价血管生成情况,Western blot检测VEGF蛋白表达。结果感染Ad-HGF的BMSCs移植2、7 d时在大鼠体内表达HGF蛋白。心功能及血流动力学检测显示,G-CSF组左室收缩压(left ventricular systolic pressure,LVSP)、左室舒张末期压力(left ventricularend-diastolic pressure,LVEDP)、LVSP上升/降低时间(dP/dtmax)、FS与对照组相比差异均无统计学意义(P>0.05);HGF组和联合治疗组与对照组相比,LVEDP显著降低,LVSP、FS和dP/dtmax显著升高(P<0.05);与HGF组相比,联合治疗组的FS和dP/dtmax升高(P<0.05)。免疫荧光双染显示心肌梗死交界区增生细胞是血管内皮细胞。联合治疗组血管密度明显高于其他3组(P<0.05),VEGF蛋白表达较其他3组明显增加(P<0.05)。结论 在大鼠心肌梗死4周时给予G-CSF联合携带HGF基因的BMSCs移植治疗,可明显改善心功能,促进心肌梗死边缘缺血区域的血管生成,其作用机制之一是增加了缺血心肌VEGF蛋白的表达。     

肝癌mRNA致敏的DC对SCID荷瘤鼠的抑瘤作用

目的通过重建人肝癌PBL-SCID嵌合模型来观察mRNA致敏的树突状细胞疫苗（mRNA DC）在体内的抑瘤效应并探讨机制。方法采用人外周血淋巴细胞腹腔注射法建立Hu-PBL-SCID鼠模型,尾静脉分别注射mRNA DC疫苗、抗CD4^＋、CD8^＋＋mRNA DC、未致敏的树突状细胞（DC）。每周1次,共两次,然后接种2×10^6HepG-2cells,观察鼠成瘤率、成瘤潜伏期、肿瘤体积以及测定特异性CTL活性。结果ELISA法可检测到鼠血清中人IgG水平,Hu-PBL-SCID嵌合模型重建成功,各组小鼠间成瘤率无明显差异,但mRNA DC组成瘤潜伏期延长,肿瘤生长缓慢,2周后肿瘤体积明显小于抗CD4^＋、CD8^＋＋mRNA DC组、DC组和PBS组,差异有统计学意义（P〈0.05）,实验组脾淋巴细胞对HepG-2细胞有特异性杀伤效应,而对胃癌SGC-7901细胞则无杀伤活性。结论mRNA致敏的树突状细胞疫苗体内能诱导产生明显的抑瘤作用。     

Xenogeneic bone marrow transplantation: II. Porcine-specific growth factors enhance porcine bone marrow engraftment in an in vitro primate microenvironment

Abstract: Establishment of mixed bone marrow chimerism in pig-to-primate transplantation, as a means of inducing specific immune tolerance, will require that both immune and nonimmune barriers be overcome. As a preliminary step in evaluating nonimmune barriers in this system, we have developed an in vitro model of engraftment in which long-term culture of porcine bone marrow-derived hematopoietic cells is supported on preformed primate bone marrow stromal layers. In the absence of cytokine supplementation, primate stromal cells were unable to support long-term porcine hematopoiesis in these cultures. Supplementation with porcine Steel Factor was required for long-term maintenance of hematopoietic progenitor cell content and total hematopoietic activity. Addition of porcine IL-3, in combination with porcine Steel Factor, increased long-term progenitor cell content and hematopoietic activity on primate stroma to levels comparable to that obtained in cultures on porcine stroma. The combination of porcine GM-CSF and Steel Factor increased progenitor cell content and hematopoietic activity early in the cultures, but had little effect in long-term cultures. The Steel Factor and IL-3 combination was species-specific in its action in these cultures, as the corresponding human cytokines were unable to effectively support long-term porcine hematopoiesis. Likewise, the combination of porcine cytokines had only minimal effects on long-term bone marrow culture of primate CD34+ cells I on primate stroma.     

Inhibitory effects on in vitro cell growth of human urothelial tumor cell lines under the combined administration of hematopoietic growth factors and clinically relevant antineoplastic agents

Summary In five of eight human transitional carcinoma cell (TCC) lines a proliferative response has been reported during exposure to interleukin-3 (IL-3), granulocyte-macrophage colony stimulating factor (GM-CSF) and granulocyte colony stimulating factor (GM-CSF). To elucidate possible growth-modulating effects of these factors combined with clinically relevant antineoplastic agents, cells of the human TCC lines EJ28 and T24 were exposed to methotrexate (MTX), vinblastine (VBL), doxorubicin (DXR) and cisplating (CDDP) with and without single or continuous exposure to IL-3, GM-CSF and G-CSF at concentrations of 1–100 ng/ml. Compared with cells exposed only to chemotherapy, significant inhibitory effects occurred as a result of continuous exposure to IL-3 or GM-CSF at the highest activities with CDDP and MTX in the T24 and EJ28 lines; continuous G-CSF administration (100 ng/ml) in combination with MTX led to significant growth inhibition in the EJ28 line. In contrast, no significant growth modulation was found on combined administration of DXR or VBL with any one of the three colony stimulating factors tested.     

Phase I/II trial of subcutaneous interleukin-2, granulocyte-macrophage colony-stimulating factor and interferon-α in patients with metastatic renal cell carcinoma

Study Type – Therapy (individual cohort) Level of Evidence 2b

OBJECTIVE

? To determine, in a phase I/II trial, the maximum tolerated dose (MTD), clinical activity and safety of concurrent subcutaneous (s.c.) interleukin‐2 (IL‐2), interferon‐α2b (IFN‐α) and granulocyte‐macrophage colony‐stimulating factor (GM‐CSF).

PATIENTS AND METHODS

? Patients with metastatic renal cell carcinoma (RCC) received on a 3+3 trial design escalating doses of s.c. GM‐CSF, IL‐2 and IFN‐α. ? Dose‐limiting toxicities (DLTs) during the first 6‐week cycle were used to determine the MTD. ? A phase II trial was then initiated to determine clinical activity.

RESULTS

? A total of sixty patients were enrolled in the study (phase I = 31; phase II = 29). ? Two DLTs were observed (G3 nausea/vomiting and fatigue) and the MTD was determined to be GM‐CSF 5.0 µg/kg/day, IL‐2 9.0 mIU/m²/day and IFN‐α 5.0 mU/m²/day. ? Patients received a median (range) of four (one to 11) cycles of therapy. G3 adverse events were reported in 10 of 31 (32%) patients. ? The overall response rate was 20% (one complete response and 11 partial responses), including patients who were rendered free of disease with surgery. ? The median progression‐free survival and overall survival were 6.0 and 23.4 months, respectively.

CONCLUSIONS

? Immunotherapy with concurrent s.c. GM‐CSF, IL‐2 and IFN‐α is generally well tolerated. ? The overall response rate observed with this combination continues to show the efficacy of immunotherapy in a selected group of metastatic RCC patients.     

Desensitization using imlifidase and EndoS enables chimerism induction in allosensitized recipient mice

Mixed hematopoietic chimerism induction as a way to foster tolerance to donor organs in recipients who have been sensitized to donor antigens is challenging. Donor‐specific antibodies (DSA) are a dominant barrier toward successful donor bone marrow engraftment. Although desensitization methods are routinely used in recipients with allosensitization for allogeneic bone marrow transplantation, engraftment is frequently unsuccessful. To overcome the barrier of prior sensitization we tested enzymatic desensitization of donor‐specific IgG using imlifidase and endoglycosidase of Streptococcus pyogenes (EndoS), which both partially block the function of DSA in mice, as a novel approach to improve murine bone marrow engraftment in primed hosts. We found that EndoS was capable of inhibiting antibody‐mediated killing of donor cells in vivo. Furthermore, the effect of EndoS depended on the titer of DSA and the genetic background of the recipients. In combination with imlifidase, EndoS improved the survival of donor bone marrow cells. Together with cyclophosphamide, bortezomib, T cell depletion, and nonlethal irradiation, imlifidase in combination with EndoS allowed allogeneic bone marrow engraftment in sensitized recipients. We conclude that enzymatic inactivation of DSA, using the combination of imlifidase and EndoS, can be used for inducing donor hematopoietic chimerism in allosensitized recipient mice in combination with other desensitization strategies.     

Hybrid resistance to parental bone marrow grafts in nonlethally irradiated mice

Resistance to parental bone marrow (BM) grafts in F1 hybrid recipients is due to natural killer (NK) cell–mediated rejection triggered through “missing self” recognition. “Hybrid resistance” has usually been investigated in lethally irradiated F1 recipients in conjunction with pharmacological activation of NK cells. Here, we investigated BM‐directed NK‐cell alloreactivity in settings of reduced conditioning. Nonlethally irradiated (1‐3 Gy) or nonirradiated F1 (C57BL6 × BALB/c) recipient mice received titrated doses (5‐20 x 10⁶) of unseparated parental BALB/c BM without pharmacological NK cell activation. BM successfully engrafted in all mice and multilineage donor chimerism persisted long‐term (24 weeks), even in the absence of irradiation. Chimerism was associated with the rearrangement of the NK‐cell receptor repertoire suggestive of reduced reactivity to BALB/c. Chimerism levels were lower after transplantation with parental BALB/c than with syngeneic F1 BM, indicating partial NK‐mediated rejection of parental BM. Activation of NK cells with polyinosinic–polycytidylic acid sodium salt poly(I:C), reduced parental chimerism in nonirradiated BM recipients but did not prevent hematopoietic stem cell engraftment. In contrast, equal numbers of parental lymph node cells were completely rejected. Hence, hybrid resistance leads to incomplete rejection of parental BM under reduced conditioning settings.