Antigen-presenting cells (APC) of mice with chronic graft-versus-host disease (GVHD) cause excessive activation-induced death of T helper cells

Both experimental and clinical forms of chronic GVHD have unique immunological features. The affected animals/individuals suffer from autoimmune disorders such as systemic lupus erythematosus (SLE), and yet they are unable to mount a self MHC-restricted T cell response to foreign antigens. Pathogenesis of the latter phenomenon was investigated in an experimental model of chronic GVHD. Chronic GVHD was induced in 8–10-week-old (B6 × C3H)F₁ mice by tail vein injection of 5 × 10⁷ spleen cells of C3H parental strain. The recipients, when tested 3 months later, were unable to mount a T helper (Th) cell response to a randomly selected immunogen, a vaccine of 10⁸ killed Mycobacterium vaccae. The animals showed evidence of generalized lymphoid hyperplasia, as indicated by GVH index >1.34, and also revealed autoantibodies against erythrocytes and dsDNA, indicating establishment of chronic GVHD. However, mice with chronic GVHD of only 3 weeks duration were able to mount the Th cell response to M. vaccae. Three consecutive immunizations of these mice at 1-week intervals, with the same immunogen, resulted in the mice becoming non-responsive to the antigen. All the three responses tested, namely the DTH, lymphoproliferation and the antibody responses, were adversely affected. The non-responsiveness induced was antigen-specific. Mice receiving two immunizations with M. vaccae responded normally to Salmonella enteritidis. Pulse treatment with cyclosporin A 0.5 mg/mouse by the i.p. route, on days 0, 1, 2, 3 and 4 at the time of immunization with M. vaccae on day 1, prevented emergence of non-responsiveness. Based on this evidence, it was concluded that repeated activation of T cells of mice with chronic GVHD induces non-responsiveness. Extent of clonal loss due to activation-induced cell death (AICD) caused by i.p. injection with a superantigen Staphylococcal enterotoxin B (SEB) was investigated in F₁ mice with chronic GVHD. I.p. injection of 25 μg/mouse of SEB induced loss of SEB responding clones in both normal F₁ mice and those having chronic GVHD; however, the extent of loss was much greater in the latter. In vitro antigen-specific proliferation of primed splenic T cells of normal F₁ mice was observed to be quite poor when antigen was presented by APC of mice with chronic GVHD of 3 weeks duration. Proliferation profiles of T cells of normal F₁ mice, in response to stimulation with concanavalin A (Con A) or SEB, were studied, using as APC irradiated spleen cells of normal F₁ mice or of F₁ mice with chronic GVHD of 3 weeks duration. With Con A and APC of normal F₁ mice, peak proliferation was observed at 48 h, which remained at the same level up to 72 h and declined thereafter, possibly due to AICD. With SEB and the normal APC, proliferation progressively peaked at 72 h and declined thereafter. With APC of mice with chronic GVHD, the 48 h proliferative responses of both Con A and SEB were comparable to those caused by APC of normal F₁ mice; however, thereafter the responses declined steeply, suggesting greater AICD. Based on these results, it was concluded that APC of mice with chronic GVHD are functionally altered to induce greater AICD.     

Soluble human leucocyte antigen-G molecules in peripheral blood haematopoietic stem cell transplantation: a specific role to prevent acute graft-versus-host disease and a link with regulatory T cells

Haematopoietic stem cell transplantation is often complicated by the life-threatening graft-versus-host disease (GVHD) which consists of an allogeneic reaction of the graft cells against the host organs. The aim of this study was to investigate the putative involvement of soluble human leucocyte antigen (sHLA) class I molecules, and particularly sHLA-G molecules, in the occurrence and/or prevention of acute GVHD (aGVHD) in allogeneic peripheral blood stem cell (PSC) transplantation. Whole sHLA class I molecules seem to be involved in aGVHD pathogenesis because detection of a high concentration of these molecules in the first month post allograft is correlated with aGVHD occurrence. Conversely, a high level of sHLA-G molecules before and after allograft could indicate good prognosis in PSC allograft transplantation. sHLA-G molecules seem to be involved in aGVHD prevention, not only because they are enriched in plasma of patients without aGVHD, but also because: (i) a positive correlation has been found between sHLA-G level and CD4+ CD25+ CD152+ natural regulatory T cell (T(reg)) frequency in the blood of transplanted patients; and (ii) the presence of CD4+ CD25+ CD152+ natural T(reg) is correlated with increased sHLA-G expression in in vitro mixed leucocyte reaction cultures. Altogether, these results support the immunomodulatory function of sHLA-G molecules that might create a regulatory network together with the natural T(reg) to foster the induction of a tolerogenic environment and improve PSC transplantation favourable outcome.     

Diminished regulatory T cells in cutaneous lesions of thymoma-associated multi-organ autoimmunity: a newly described paraneoplastic autoimmune disorder with fatal clinical course

Thymoma-associated multi-organ autoimmunity is a rare, autoimmune disease that causes colitis, liver dysfunction and cutaneous graft-versus-host (GVH)-like skin damage. This paraneoplastic autoimmune disorder may be due to inadequate T cell selection in the tumour environment of the thymus. Although sporadic case reports have revealed its clinical features, little is known about its pathological mechanism. By comparing the skin-infiltrating T cell subsets with those of GVH disease (GVHD) and other inflammatory skin diseases, we sought to elucidate the pathological mechanism of thymoma-associated multi-organ autoimmunity. Histopathological and immunohistochemical analysis of skin biopsies was performed for three patients with thymoma-associated multi-organ autoimmunity. Histopathological findings of thymoma-associated multi-organ autoimmunity were indistinguishable from those of patients with acute GVHD, although the aetiologies of these diseases are completely different. The frequency of regulatory T cells (T(regs)) is reduced in cutaneous lesions and CD8+ cytotoxic T lymphocytes that massively infiltrate into the epidermis of patients with thymoma-associated multi-organ autoimmunity. Additionally, the ratio of T helper type 17 (Th17) cells to CD4+ cells in patients with thymoma-associated multi-organ autoimmunity and acute GVHD was higher than that in healthy controls, but similar to that in psoriasis vulgaris patients. Similarity of the skin-infiltrating T cell subsets with those of acute GVHD suggested that skin damage in patients with thymoma-associated multi-organ autoimmunity might be induced by self-reactive cytotoxic T lymphocytes under the diminished suppressive capacity of T(regs).     

Differential effects of sex hormones on autoantibody production and proteinuria in chronic graft-versus-host disease-induced experimental lupus nephritis

In patients with systemic lupus erythematosus, the female-to-male ratio is as high as 10:1. Sex hormones are thought to play a role in this difference in susceptibility. In a previous study, we demonstrated a high susceptibility of female mice to the development of glomerulonephritis after induction of chronic graft-versus-host disease (GVHD), compared with male mice. In order to unravel further this gender-related difference (C57Bl/10*DBA/2)F¹ hybrid mice were either castrated or ovariectomized and treated with 17β-ethinyloestradiol or testosterone-decanoate preceding the induction of chronic GVHD. Testosterone-decanoate reduced significantly the development of albuminuria in females. In contrast, proteinuria of 17β-ethinyloestradiol-treated female mice was in the same range as that of sham-operated mice. Autoantibody levels against glomerular basement membrane, renal tubular epithelium, dsDNA and ssDNA, as determined by ELISA, were higher in 17β-ethinyloestradiol-treated female mice than in all other groups. Immunofluorescence studies showed the presence of immunoglobulin and complement deposits in glomeruli of all animals, without significant differences between the experimental groups. Our findings confirm earlier observations, in that testosterone-decanoate is shown to be an inhibitory compound, whereas 17β-ethinyloestradiol has stimulating properties in autoimmunity. Moreover, our results show for the first time differential hormonal effects on autoantibody levels and proteinuria in experimental lupus nephritis.     

Expression of membrane-bound IL-15 by bone marrow fibroblast-like stromal cells in aplastic anemia

In order to explore the relationship between IL-15 and aplastic anemia (AA), bone marrow (BM) fibroblast-like stromal cells (BMFSCs) were obtained from BM samples of 23 AA patients by density centrifugation and primary culturing in vitro. Indirect immunofluorescence labeling as well as flow cytometry and confocal laser scanning microscopy analysis were used to determine the expression of membrane-bound IL-15 (mIL-15) on the surface of BMFSCs derived from AA patients (AA-BMFSCs). The effects of IFN-gamma and cyclosporin A (CsA) on the expression of mIL-15 were also investigated. [(3)H]thymidine incorporation test as well as specific antibody inhibition and Transwell separation experiment was adopted to functionally evaluate the expression of mIL-15 on the surface of AA-BMFSCs. mIL-15 was found to be over-expressed on the surface of AA-BMFSCs. IFN-gamma further significantly up-regulated its expression, which, however, was inhibited by CsA. Interestingly, a tight correlation was found between the expression of mIL-15 and IL-15Ralpha on the surface of AA-BMFSCs. AA-BMFSCs had the capability to stimulate the proliferation of T lymphocytes, which was partly or completely inhibited by using neutralizing anti-IL-15Ralpha antibody, neutralizing anti-IL-15 antibody, blocking anti-IL-2/15Rgamma(c) mAb or Transwell chambers with a 0.3-mum pore size membrane to block the direct cell-to-cell contact between AA-BMFSCs and T cells. Apparently, BMFSCs as the most important component of BM hematopoietic microenvironment usually over-express mIL-15 in AA patients. Therefore, AA-BMFSCs may indirectly participate in the T cell-mediated destruction of hematopoietic progenitors in AA by recruiting T cells to BM and stimulating them in situ.     

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.     

The identification and characteristics of IL-22-producing T cells in acute graft-versus-host disease following allogeneic bone marrow transplantation

Graft-versus-host disease (GVHD) remains the major obstacle for allogeneic bone marrow transplantation, in which many proinflammatory cytokines secreted by alloreactive donor T cells are involved. Role of IL-22 as a member of IL-10 family in GVHD is still disputed and the properties of IL-22-producing cells are unclear. We demonstrated here that CD4⁺ T cells but not CD8⁺ T cells involved in GVHD were the main cellular source of donor-derived IL-22. Th1 and Th17 cells were detected not only express classical cytokine IFN-γ or IL-17, but also contributed to IL-22 secretion in GVHD. Th22 cells characterized by the independent secretion of IL-22 were identified and occupied almost half percentage of IL-22-producing CD4⁺ T cells. The frequency of IL-22-producing CD4⁺ T cells showed dynamic changes with the development of GVHD. Finally, we observed that IL-22-producing CD4⁺ T cells in GVHD mouse carried CD62L⁻CD44^high/low surface markers. In conclusion, we illuminate the characteristics of donor-derived IL-22-producing CD4⁺ T cells, which may have potent implication for further study of pathogenesis of GVHD.     

骨组织工程的种子细胞--骨髓基质细胞的研究进展

骨髓基质细胞作为骨组织工程的种子细胞具有广阔前景.许多实验证实骨髓基质细胞具有间充质干细胞特性,表现为较强的增殖能力和向多种间充质细胞分化的潜能.目前已建立了体外培养骨髓基质干细胞的方法,而且正在摸索进一步纯化的方法和诱导分化的条件.已有利用其成骨特性体内移植实验,表明在适当的条件下,接种在组织工程材料上的骨髓基质细胞可以形成新骨.     

Content of stromal precursor cells in heterotopic transplants of bone marrow in CBA mice of various ages

Efficiency of colony formation of stromal precursor cells in cultured bone marrow transplants from old (24 month) CBA mice implanted to young (2-month-old) mice almost 3-fold surpassed that in cultured transplants implanted to old recipients. The content of nucleated cells in bone marrow transplants from senescence accelerated mice SAMP increased more than 2-fold, if SAMR mice with normal aging rate were used as the recipients instead of SAMP mice. Bone marrow taken from old and young CBA mice endured the same number of transplantations if the recipient mice were of the same age (5 month). It was concluded that stromal tissue considerably changes with age and is under strict control of the body.     

巨噬细胞型骨髓基质细胞对肿瘤抗原提呈的体外实验研究

目的　探讨骨髓基质细胞对肿瘤抗原的提呈功能。方法　小鼠骨髓贴壁细胞经 Ｇ Ｍ Ｃ Ｓ Ｆ 诱导,形成以成熟巨噬细胞为主的基质细胞,用小鼠红白血病细胞 Ｆ Ｂ Ｌ３ 肿瘤抗原刺激,然后再与 Ｆ Ｂ Ｌ３ 肿瘤抗原致敏的 Ｔ 淋巴细胞混合培养。结果　骨髓基质细胞经 Ｆ Ｂ Ｌ３ 肿瘤抗原刺激后, Ｔ Ｎ Ｆα和 Ｉ Ｌ１β的分泌水平明显升高,经抗原预激的骨髓基质细胞能特异性地刺激同种抗原致敏的 Ｔ 淋巴细胞增殖和分泌高水平的 Ｉ Ｌ２ 。单抗阻断试验发现, Ｍ Ｈ ＣⅡ类分子和 Ｂ７２ 分子的联合阻断能有效地抑制致敏 Ｔ 淋巴细胞分泌 Ｉ Ｌ２ 。结论　本实验证实骨髓基质细胞具有抗原提呈功能, Ｍ Ｈ ＣⅡ类分子和 Ｂ７２ 分子在其抗原提呈中发挥了重要作用。     

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.     

Differentiation of bone marrow stromal stem cells into cardiomyocyte-like cells in different mammalian species

We describe the possibility of obtaining cardiomyocyte-like cell cultures from rat, guinea pig, and human bone marrow stromal stem cells. The content of troponin I-positive cells attains 35-45% of the total number of cells in the cultures and persists at this level for up to 4 months under differentiation conditions. Spontaneous contractions of cardiomyocyte-like cells were observed after the formation of cell monolayer under differentiation conditions.     

骨髓基质细胞对中脑神经干细胞分化为神经元的诱导作用

目的:观察成年大鼠骨髓基质细胞诱导新生大鼠中脑神经干细胞分化为神经元的机制。方法:采用骨髓基质细胞和神经干细胞共培养方法,通过显微镜观察神经干细胞的分化状态;使用免疫组织化学技术,分析神经元在神经干细胞后代中所占的比例。结果:(1)骨髓基质细胞可诱导神经干细胞分化为高比例神经元;(2)骨髓基质细胞可促进神经元的存活。结论:骨髓基质细胞可提供神经干细胞分化为神经元和促进神经元存活的信号物质。     

Origination of stromal precursor cells replenishing the population of these cells in heterotopic mouse bone marrow transplants after curettage in recipients

Curettage of bone marrow cavities of two bones (femoral and crural) in recipient mice causes a drastic (more than 7-fold) increase in the count of stromal precursor cells in heterotopic bone marrow transplants. Stromal colonies in cell cultures from these transplants consist of fibroblasts with an appreciable admixture of macrophages. All Y chromosome-typed colonies from cultures of female donor bone marrow transplants in recipient males (intact and subjected to curettage) contained cells carrying and not carrying Y chromosome. Quantitative results of Y chromosome typing of cells from colonies corresponded to the fibroblast/macrophage ratio in colonies and the predominant localization of the label corresponded to predominant localization of macrophages (at the periphery of colonies). The results indicate that the pool of bone marrow stromal precursor cells under conditions of increased demands originates from local sources, which confirms ample data on inability of these cells to migration. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 143, No. 5, pp. 568–567, May, 2007     

丹参诱导大鼠骨髓间充质干细胞向神经样细胞分化

目的:探讨骨髓间充质干细胞(marrow stromal stem cells,MSCs)向神经细胞分化中神经蛋白分子及相关基因的表达情况。方法:分离提取大鼠的MSCs,体外培养扩增。用含丹参的无血清的L-DMEM培养基进行诱导,并以不含丹参的无血清L-DMEM培养基作为对照。提取两组的MSCs总RNA,RT-PCR检测ngn-1、mash-1的表达。结果:丹参诱导90 min后,细胞发生了明显的形态学变化,大多数细胞转变为类似双极或多极神经元样形态,伸出轴突或树突样突起。免疫细胞化学显示诱导后的MSCs表现为nestin、NSE、GFAP染色阳性,对照组为阴性。未经诱导的MSCs ngn-1,mash-1 mRNA为阴性,诱导后有表达。结论:丹参可诱导大鼠MSCs向神经前体细胞和神经细胞分化。MSCs向神经元样的分化可能与ngn-1,mash-1有关。     

Ghrelin抑制小鼠骨髓基质细胞成脂分化

目的观察胃促生长素ghrelin对原代培养小鼠骨髓基质细胞成脂分化的影响。方法体外培养小鼠骨髓基质细胞,MDI诱导剂诱导细胞成脂分化,显微镜观察细胞形态变化;油红O染色法检测细胞甘油三酯含量,化学比色法测定碱性磷酸酶(ALP)活性;MTT法检测细胞克隆化扩增活动,RT-PCR检测过氧化物酶体增殖物激活受体γ2(PPARγ2)和丝氨酸蛋白酶脂肪因子adipsinmRNA表达,Westernblot检测PPARγ2蛋白表达。结果Ghrelin能够剂量依赖性(10-9、10-8、10-7mol/L)地抑制骨髓基质细胞成脂分化,升高ALP活性(P<0·05或P<0·01)。Gh-relin能够降低PPARγ2和adipsinmRNA以及PPARγ2蛋白表达(P<0·05)。Ghrelin对细胞成脂分化早期的克隆化扩增没有显著影响。结论Ghrelin能够显著抑制体外培养小鼠骨髓基质细胞成脂分化,该作用可能与抑制PPARγ2表达有关。     

Effect of curettage of the medullary cavity on bone marrow stromal precursor cells

Changes in the number of stromal bone marrow precursor cells in guinea pigs after curettage of the medullary cavity were studied by cloning and monolayer cultures in vitro. Curettage was shown to remove about half of the fibroblast colony forming cells (FCFC) from the bone marrow. Later, the number of FCFC in the curetted limb fell to reach a minimum after 12 h. Starting from 24 h their number increased. By the 7th–12th day the number of FCFC reached the normal level, and by the 20th day it was 2.5 times higher than normal. The number of FCFC in the contralateral limb between 6 h and 20 days after curettage was 2–2.5 times greater than normal.Laboratory of Immunomorphology, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR P. A. Vershilova.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 9, pp. 362–365, September, 1978.     

右归丸诱导大鼠骨髓基质细胞分化为神经样细胞的研究

目的:探讨右归丸体外诱导大鼠骨髓基质细胞分化为神经样细胞。方法:密度梯度离心法结合贴壁培养法培养骨髓基质细胞,并利用右归丸诱导骨髓基质细胞分化为神经样细胞,设为空白对照组,右归丸组。结果:诱导7 d后,与空白对照组相比较,右归丸组细胞显示为典型的神经细胞样形态,细胞NSE、Nestin和GFAP阳性率明显增高(P<0.05)。结论:右归丸可以体外诱导大鼠骨髓基质细胞分化为神经样细胞。     

Central and peripheral nerve regeneration by transplantation of Schwann cells and transdifferentiated bone marrow stromal cells

In contrast to the peripheral nervous system (PNS), little structural and functional regeneration of the central nervous system (CNS) occurs spontaneously following injury in adult mammals. The inability of the CNS to regenerate is mainly attributed to its own inhibitorial environment such as glial scar formation and the myelin sheath of oligodendrocytes. Therefore, one of the strategies to promote axonal regeneration of the CNS is to experimentally modify the environment to be similar to that of the PNS. Schwann cells are the myelinating glial cells in the PNS, and are known to play a key role in Wallerian degeneration and subsequent regeneration. Central nervous system regeneration can be elicited by Schwann cell transplantation, which provides a suitable environment for regeneration. The underlying cellular mechanism of regeneration is based upon the cooperative interactions between axons and Schwann cells involving the production of neurotrophic factors and other related molecules. Furthermore, tight and gap junctional contact between the axon and Schwann cell also mediates the molecular interaction and linking. In this review, the role of the Schwann cell during the regeneration of the sciatic (representing the PNS) and optic (representing the CNS) nerves is explained. In addition, the possibility of optic nerve reconstruction by an artificial graft of Schwann cells is also described. Finally, the application of cells not of neuronal lineage, such as bone marrow stromal cells (MSCs), in nerve regeneration is proposed. Marrow stromal cells are known as multipotential stem cells that, under specific conditions, differentiate into several kinds of cells. The strategy to transdifferentiate MSCs into the cells with a Schwann cell phenotype and the induction of sciatic and optic nerve regeneration are described.