同种异基因骨髓移植中控制移植物抗宿主病和保留移植物抗白血病的新策略

同种异基因骨髓移植(allo-BMT)对白血病的治疗效果已得到广泛承认，然而移植物抗宿主病(GVHD)和白血病复发是移植成功的两个主要障碍。积累的研究已证明异基因骨髓移植物中的T淋巴细胞是GVHD重要效应细胞，同时具有移植物抗白血病(GVL)、抗感染和预防宿主抗移植物效     

供体CD+4CD+25T细胞及调控基因FOXP3在急性移植物抗宿主病中的作用

目的 探讨供体CD+4CD+25T细胞亚群、FOXP3调控基因的表达与受者移植物抗宿主病(GVHD)的相关性.方法 (1)30例异基因造血干细胞移植(allo-HSCT),采用免疫荧光标记和流式细胞术检测并比较供体粒细胞集落刺激因子(G-CSF)动员前外周血、动员后采集物CD+4CD+25T细胞亚群比例,随访异基因移植后GVHD的发生率和严重程度.(2)应用RT-PCR技术检测供体FOXP3基因表达情况,分析其与GVHD、疾病复发的相关性.结果 (1)所有患者均获造血重建,粒细胞绝对数(ANC)≥0.5×109/L的中位时间为14(12～15)d,PLT≥20×109/L为18(15～25)d.30例allo-HSCT,中位随访时间12.8(8～16)个月,Ⅰ～Ⅳ度急性GVHD分别为3、4、3、5例.慢性GVHD 6例.(2)供体G-CSF动员前外周血、动员后采集物CD+4CD+25T细胞亚群分别为(2.67±0.38)%、(5.01±1.33)%,两者相比差异无统计学意义(P＞0.05).(3)移植后无急性GVHD组、Ⅰ～Ⅱ度急性GVHD组、Ⅲ～Ⅳ度急性GVHD组供体CD+4CD+25T细胞亚群分别为(5.05±1.34)%、(4.17±1.73)%、(1.98±1.10)%.其中Ⅰ～Ⅱ度急性GVHD组与Ⅲ～Ⅳ度急性GVHD组相比差异有统计学意义(P=0.04),无急性GVHD组与Ⅲ～Ⅳ度急性GVHD组相比差异有统计学意义(P=0.002).(4)30例allo-HSCT,7例FOXP3基因表达阳性,5/7例移植后无急性GVHD,其中3例移植后复发,另2/7例移植后Ⅰ度急性GVHD,Ⅱ～Ⅳ度急性GVHD患者FOXP3均不表达.结论 (1)供体CD+4CD+25T细胞亚群比例与受者急性GVHD的发生具有一定的相关性,提高供体CD+4CD+25T细胞数量有望减低移植后急性GVHD发生率.(2)供体移植物FOXP3基因表达阳性,与移植后有无严重急性GVHD发生存在一定相关性.     

异基因造血干细胞移植后T细胞免疫重建与移植物抗宿主病

异基因造血干细胞移植(Allo-HSCT)后的免疫重建与移植物抗肿瘤／白血病(GVT／GVL)效应,及移植物抗宿主病(GVHD)、移植后感染等均有密切关系。T细胞是细胞免疫、体液免疫的调节与效应细胞,在移植后的免疫重建中占有重要位置。由于供者T细胞活化是GVHD发生的关键环     

调节性T细胞与移植物抗宿主病相关性的研究进展

异基因造血干细胞移植(allo-HSCT)已被广泛应用于治疗多种遗传性疾病、恶性或非恶性血液系统疾病,然而移植物抗宿主病(GVHD)仍然是导致allo-HSCT后死亡的最重要的并发症之一。目前应用多种免疫抑制剂防治GVHD已达到一定的治疗疗效,但却大大增加了感染和复发的几率。利用免疫系统内在的调节机制调节异基因免疫应答,控制GVHD的发生,同时保留抗感染及抗肿瘤免疫已成为目前移植耐受研究的焦点。调节性T细胞可通过“主动”的方式抑制免疫系统对自身和外来抗原的应答,在维持机体免疫耐受和免疫应答稳态方面具有非常重要的作用。CD4 CD2 …     

移植物抗宿主反应中抗原提呈坌田胞作用白勺研究进展

同种异基因造血干细胞移植（allo—HSCT）中同时存在2种同种异基因免疫反应一移植物抗白血病效应（GVL）和移植物抗宿主病（GVHD）。这2种免疫反应均是由于供者淋巴细胞活化后对受者的靶组织攻击后所产生的，GVHD是对受者正常的组织如肝脏、皮肤和消化道等的攻击，而GVL则是对白血病细胞的攻击。     

T细胞比例对大鼠移植物抗宿主反应的影响

目的：研究移植物和受体的T细胞比例与移植物抗宿主反应（GVHD）的关系。方法：受体SD大鼠和供体Wistar大鼠共40对．按移植物与受体的T细胞比例1：1、2：1、4：1和对照组分为4组进行移植，并观察移植后GVHD的发生及其程度。结果：4组大鼠中1：1和2：1组的GVHD最轻，与对照组比较差异有统计学意义（P〈0．01），而4：1组的GVHD与对照组比较差异则无统计学意义（P〉0．05）。结论：移植物内T细胞与受体循环血内的T细胞绝对值之比介于1：1与2：1之间较为合适；按此比例进行的大鼠移植，GVHD较轻。     

间充质干细胞在治疗移植物抗宿主病中的应用

移植物抗宿主病(graft-versus-host disease,GVHD)是在临床移植过程中,供体移植物以T细胞为主的淋巴细胞识别宿主抗原致敏,从而导致其直接或间接攻击宿主器官产生病理损伤的疾病。临床上根据患者病情严重程度将GVHD分为4度,主要涉及皮肤、肝脏和肠道反应(见表1)。此外,临床上还根据GVHD在移植后发生的时间将其分为     

干细胞移植后CD+4CD+25T细胞与慢性移植物抗宿主病的关系

CD4^＋CD25^＋细胞是一类具有独特免疫抑制功能的调节性T细胞亚群，异基因外周血干细胞移植（ALLO-PBSCT）后供者型CD；cD未细胞与慢性移植物抗宿主病（cGVHD）发生的关系所知甚少。我们于2002年3月至2003年9月对18例白血病患者进行了ALLO-PBSCT术，并对T细胞与cGVHD的关系进行了研究。     

猪抗人淋巴细胞免疫球蛋白联合CD25单抗用于恶性血液病单倍体移植中急、慢性移植物抗宿主病预防的临床分析

目的 探讨猪抗人淋巴细胞免疫球蛋白(ALG)联合CD25单抗在恶性血液病单倍体移植中预防急、慢性移植物抗宿主病(GVHD)的疗效和安全性.方法 回顾性分析我院2018年5月～2020年6月首次单倍体移植中行ALG联合CD25单抗预防GVHD的恶性血液病患者18例,记录预防期间的不良反应、干细胞植入时间、急性移植物抗宿主...     

异基因造血干细胞移植后FOXP3动态监测的临床意义

目的 探讨FOXP3mRNA水平的动态变化在异基因造血干细胞移植(allo-HSCT)中的临床意义.方法 allo-HSCT患者27例,12例采用短程甲氨蝶呤联合环孢素A(MTX CsA)预防移植物抗宿主病(GVHD),15例加用抗CD25强化GVHD预防;发生急性移植物抗宿主病(aGVHD)者11例.采用实时荧光定量PCR反应动态监测allo-HScT患者移植预处理前、移植当天、移植后1、2、4周及aGVHD发生时外周血FOXP3mRNA水平,分析FOXP3mRNA水平的变化与aGVHD发生的相互关系.结果 抗CD25对FOXIr3mRNA水平无影响;Ⅰ～Ⅱ度和Ⅲ～Ⅳ度aGVHD组发生aGVHD时FOXP3mRNA水平均较发生前降低,差异具有统计学意义(P<0.05).结论 FOXP3是CD4 CD25 Treg细胞的特异性标志,对CD4 CD25 Treg细胞的发育和功能发挥起重要作用,对aGVHD的发生具有保护作用,可作为临床监测aGVHD发生的重要指标之一.     

CD8+ but not CD4+ T cells require cognate interactions with target tissues to mediate GVHD across only minor H antigens, whereas both CD4+ and CD8+ T cells require direct leukemic contact to mediate GVL

Whether T-cell antigen receptors (TCR) on donor T cells require direct interactions with major histocompatibility complex class I or class II (MHCI/MHCII) molecules on target cells to mediate graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) is a fundamental question in allogeneic stem-cell transplantation (alloSCT). In MHC-mismatched mouse models, these contacts were not required for GVHD. However, this conclusion may not apply to MHC-matched, multiple minor histocompatibility antigen-mismatched alloSCT, the most common type performed clinically. To address this, we used wild-type (wt)-->MHCI-/- or wt-->MHCII-/- bone marrow chimeras as recipients in GVHD experiments. For GVL experiments, we used MHCI-/- or MHCII-/- chronic-phase CML cells created by expressing the BCR-ABL cDNA in bone marrow from MHCI-/- or MHCII-/- mice. TCR/MHCI contact was obligatory for both CD8-mediated GVHD and GVL. In contrast, CD4 cells induced GVHD in wt-->MHCII-/- chimeras, whereas MHCII-/- mCP-CML was GVL-resistant. Donor CD4 cells infiltrated affected skin and bowel in wt-->MHCII-/- recipients, indicating that they mediated GVHD by acting locally. Thus, CD4 cells use distinct effector mechanisms in GVHD and GVL: direct cytolytic action is required for GVL but not for GVHD. If these noncytolytic pathways can be inhibited, then GVHD might be ameliorated while preserving GVL.     

Inhibition of CD4+CD25+ regulatory T-cell function by calcineurin-dependent interleukin-2 production

CD4+CD25+ regulatory T (Treg) cells control immunologic tolerance and antitumor immune responses. Therefore, in vivo modification of Treg function by immunosuppressant drugs has broad implications for transplantation biology, autoimmunity, and vaccination strategies. In vivo bioluminescence imaging demonstrated reduced early proliferation of donor-derived luciferase-labeled conventional T cells in animals treated with Treg cells after major histocompatibility complex mismatch bone marrow transplantation. Combining Treg cells with cyclosporine A (CSA), but not rapamycin (RAPA) or mycophenolate mofetil (MMF), suppressed Treg function assessed by increased T-cell proliferation, graft-versus-host disease (GVHD) severity, and reduced survival. Expansion of Treg and FoxP3 expression within this population was lowest in conjunction with CSA, suggesting that calcineurin-dependent interleukin 2 (IL-2) production is critically required for Treg cells in vivo. The functional defect of Treg cells after CSA exposure could be reversed by exogenous IL-2. Further, the Treg plus RAPA combination preserved graft-versus-tumor (GVT) effector function against leukemia cells. Our data indicate that RAPA and MMF rather than CSA preserve function of Treg cells in pathologic immune responses such as GVHD without weakening the GVT effect.     

Kinetic of regulatory CD25high and activated CD134+ (OX40) T lymphocytes during acute and chronic graft-versus-host disease after allogeneic bone marrow transplantation

Graft-versus-host disease (GVHD) is still a major complication after allogeneic stem cell transplantation. In murine models, freshly isolated or ex vivo expanded CD4(+)CD25(high) regulatory T cells (Treg) are able to ameliorate GVHD while maintaining graft-versus-leukaemia reactions. However, in the human setting, prospective studies of this population and its interaction with activated non-regulatory CD134(+) (OX40) lymphocytes during post-transplant follow-up are lacking. In this study, we prospectively quantified CD4(+)CD25(high) and activated CD134(+) lymphocytes in 119 peripheral blood samples from 35 consecutive patients who underwent allogeneic bone marrow transplantation (BMT). Fifty-five samples obtained less than 100 d after allogeneic BMT, were not statistically different regarding CD4(+)CD25(high) Treg or CD134(+) lymphocytes compared with those obtained from patients with (n = 35) or without (n = 20) acute GVHD. Chronic GVHD was associated with a small, but not statistically significant, increase in the number of Treg (9.9 vs. 6.7 x 10(6)/L). However, the CD134/CD25(high) ratio was significantly higher during chronic GVHD (cGHVD) when compared with either patients without cGVHD (67.7 +/- 40.3 vs. 4.0 +/- 0.9, P < 0.01) or cGVHD after treatment (67.7 +/- 40.3 vs. 3.7 +/- 0.8, P < 0.01). Our findings suggest that the suppressive activity of CD4(+)CD25(high) Treg could be abrogated in vivo during cGVHD by CD134 expression in a much higher number of activated donor T lymphocytes. In addition to CD4(+)CD25(high)ex vivo expansion protocols, OX40 blocking might be crucial to optimize the use of Treg to prevent GVHD.     

Only the CD62L+ subpopulation of CD4+CD25+ regulatory T cells protects from lethal acute GVHD

CD4+CD25+ regulatory T (Treg) cells are potent modulators of alloimmune responses. In murine models of allogeneic bone marrow transplantation, adoptive transfer of donor CD4+CD25+ Treg cells protects recipient mice from lethal acute graft-versus-host disease (aGVHD) induced by donor CD4+CD25- T cells. Here we examined the differential effect of CD62L+ and CD62L- subsets of CD4+CD25+ Treg cells on aGVHD-related mortality. Both subpopulations showed the characteristic features of CD4+CD25+ Treg cells in vitro and did not induce aGVHD in vivo. However, in cotransfer with donor CD4+CD25- T cells, only the CD62L+ subset of CD4+CD25+ Treg cells prevented severe tissue damage to the colon and protected recipients from lethal aGVHD. Early after transplantation, a higher number of donor-type Treg cells accumulated in host mesenteric lymph node (LN) and spleen when CD4+CD25+CD62L+ Treg cells were transferred compared with the CD62L- subset. Subsequently, CD4+CD25+CD62L+ Treg cells showed a significantly higher capacity than their CD62L- counterpart to inhibit the expansion of donor CD4+CD25- T cells. The ability of Treg cells to efficiently enter the priming sites of pathogenic allo-reactive T cells appears to be a prerequisite for their protective function in aGVHD.     

自身免疫性甲状腺疾病和CD4~+CD25~+调节性T细胞

自身免疫性甲状腺疾病(AITD)的发生及发展与CD4~+CD25~+调节性T细胞(Treg细胞)的数量和功能密切相关.动物实验证明Treg细胞可抑制AITD的发生.如果清除动物体内的该类细胞,可导致AITD发病或使原有的甲状腺疾病加重,Treg细胞通过抑制效应性T细胞的激活而发挥对AITD的影响作用.无论是胸腺还是外周,不同诱导体系来源的Treg细胞均对AITD有影响作用.     

Differential use of Fas ligand and perforin cytotoxic pathways by donor T cells in graft-versus-host disease and graft-versus-leukemia effect

In allogeneic bone marrow transplantation (BMT) donor T cells are primarily responsible for antihost activity, resulting in graft-versus-host disease (GVHD), and for antileukemia activity, resulting in the graft-versus-leukemia (GVL) effect. The relative contributions of the Fas ligand (FasL) and perforin cytotoxic pathways in GVHD and GVL activity were studied by using FasL-defective or perforin-deficient donor T cells in murine parent --> F1 models for allogeneic bone marrow transplantation. It was found that FasL-defective B6.gld donor T cells display diminished GVHD activity but have intact GVL activity. In contrast, perforin-deficient B6.pfp(-/-) donor T cells have intact GVHD activity but display diminished GVL activity. Splenic T cells from recipients of B6.gld or B6.pfp(-/-) T cells had identical proliferative and cytokine responses to host antigens; however, splenic T cells from recipients of B6.pfp(-/-) T cells had no cytolytic activity against leukemia cells in a cytotoxicity assay. In experiments with selected CD4(+) or CD8(+) donor T cells, the FasL pathway was important for GVHD activity by both CD4(+) and CD8(+) T cells, whereas the perforin pathway was required for CD8-mediated GVL activity. These data demonstrate in a murine model for allogeneic bone marrow transplantation that donor T cells mediate GVHD activity primarily through the FasL effector pathway and GVL activity through the perforin pathway. This suggests that donor T cells make differential use of cytolytic pathways and that the specific blockade of one cytotoxic pathway may be used to prevent GVHD without interfering with GVL activity.     

Host MHC class II+ antigen-presenting cells and CD4 cells are required for CD8-mediated graft-versus-leukemia responses following delayed donor leukocyte infusions

Following bone marrow transplantation, delayed donor leukocyte infusions (DLIs) can induce graft-versus-leukemia (GVL) effects without graft-versus-host disease (GVHD). These antitumor responses are maximized by the presence of host hematopoietic antigen-presenting cells (APCs) at the time of DLI. Using a tumor-protection model, we demonstrate here that GVL activity following administration of DLIs to established mixed chimeras is dependent primarily on reactivity to allogeneic MHC antigens rather than minor histocompatibility or tumor-associated antigens. CD8(+) T-cell-dependent GVL responses against an MHC class II-negative tumor following delayed DLI require CD4(+) T-cell help and are reduced significantly when host APCs lack MHC class II expression. CD4(+) T cells primed by host APCs were required for maximal expansion of graft-versus-host reactive CD8(+) T cells but not their synthesis of IFN-gamma. In contrast, the GVL requirement for CD4(+) T-cell help was bypassed almost completely when DLI was administered to freshly irradiated recipients, indicating that the host environment is a major factor influencing the cellular mechanisms of GVL.     

自身免疫性甲状腺疾病和CD4~+CD25~+调节性T细胞

自身免疫性甲状腺疾病(AITD)的发生及发展与CD4~+CD25~+调节性T细胞(Treg细胞)的数量和功能密切相关.动物实验证明Treg细胞可抑制AITD的发生.如果清除动物体内的该类细胞,可导致AITD发病或使原有的甲状腺疾病加重,Treg细胞通过抑制效应性T细胞的激活而发挥对AITD的影响作用.无论是胸腺还是外周,不同诱导体系来源的Treg细胞均对AITD有影响作用.     

自身免疫性甲状腺疾病和CD4~+CD25~+调节性T细胞

自身免疫性甲状腺疾病(AITD)的发生及发展与CD4~+CD25~+调节性T细胞(Treg细胞)的数量和功能密切相关.动物实验证明Treg细胞可抑制AITD的发生.如果清除动物体内的该类细胞,可导致AITD发病或使原有的甲状腺疾病加重,Treg细胞通过抑制效应性T细胞的激活而发挥对AITD的影响作用.无论是胸腺还是外周,不同诱导体系来源的Treg细胞均对AITD有影响作用.     

Rapamycin and IL-2 reduce lethal acute graft-versus-host disease associated with increased expansion of donor type CD4+CD25+Foxp3+ regulatory T cells

Previous work has demonstrated that both rapamycin (RAPA) and IL-2 enhance CD4?CD25?Foxp3? regulatory T-cell (Treg) proliferation and function in vitro. We investigated whether the combination of RAPA plus IL-2 could impact acute GVHD induction after bone marrow transplantation (BMT). RAPA plus IL-2 resulted in improved survival and a reduction in acute GVHD lethality associated with an increased expansion of donor type CD4?Foxp3? Tregs and reduced CD4?CD25? conventional T cells (Tcons). RAPA plus IL-2, but not either drug alone, increased both expansion of donor natural Tregs and conversion of induced Tregs from donor CD25? Tcons while IL-2 alone increased conversion of Tregs from CD25? Tcon. RAPA plus IL-2 treatment resulted in less production of IFN-γ and TNF, cytokines known to be important in the initiation of acute GVHD. These studies indicate that the pharmacologic stimulation of T cells with IL-2 and the suppression of Tcon proliferation with RAPA result in a selective expansion of functional Tregs and suppression of acute GVHD.