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.     

Chronic graft-versus-host disease is associated with increased numbers of peripheral blood CD4+CD25high regulatory T cells

Chronic graft-versus-host disease (cGVHD) is characterized by a state of profound immunodeficiency in association with alloreactive and autoimmune phenomena. These observations indicate an impairment of immunologic tolerance that could involve both central and peripheral mechanisms. Defective thymic function may contribute to dysregulation of central tolerance, but few studies have addressed peripheral tolerance. Recently a population of CD4+CD25+ T cells (Treg cells) has been characterized, which controls immunologic reactivity in vivo and which on transfer can prevent experimental acute GVHD. We investigated the number and function of peripheral blood CD4+CD25high T cells in patients more than 100 days after allogeneic hematopoietic stem cell transplantation. Patients with cGVHD had markedly elevated numbers of CD4+CD25high T cells as compared to patients without GVHD. CD4+CD25high T cells derived from patients in both groups were of donor origin, lacked markers of recent activation, and expressed intracellular CD152. In contrast to controls, CD4+CD25high T cells derived from patients with cGVHD were characterized by lower surface CD62L expression. In vitro, CD4+CD25high T cells were hyporesponsive to polyclonal stimulation and suppressed the proliferation and cytokine synthesis of CD4+CD25- cells, an effect that was independent of interleukin 10. These results indicate that chronic graft-versus-host injury does not occur as a result of Treg cell deficiency.     

In vivo-activated CD103+CD4+ regulatory T cells ameliorate ongoing chronic graft-versus-host disease

CD103 (alphaEbeta7) has been shown to be an excellent marker for identifying in vivo-activated FoxP3(+)CD4(+) regulatory T (Treg) cells. It is unknown whether reinfusion of in vivo-activated donor-type CD103(+) Treg cells from recipient can ameliorate ongoing chronic graft-versus-host disease (GVHD). Here, we showed that, in a chronic GVHD model of DBA/2 (H-2(d)) donor to BALB/c (H-2(d)) recipient, donor-type CD103(+) Treg cells from recipients were much more potent than CD25(hi) natural Treg cells from donors in reversing clinical signs of GVHD and tissue damage. Furthermore, in contrast to CD25(hi) natural Treg cells, CD103(+) Treg cells expressed high levels of CCR5 but low levels of CD62L and directly migrated to GVHD target tissues. In addition, the CD103(+) Treg cells strongly suppressed donor CD4(+) T-cell proliferation; they also induced apoptosis of in vivo-activated CD4(+) T and B cells and significantly reduced pathogenic T and B cells in GVHD target tissues. These results indicate that CD103(+) Treg cells from chronic GVHD recipients are functional, and reinfusion of the CD103(+) Treg cells can shift the balance between Treg cells and pathogenic T cells in chronic GVHD recipients and ameliorate ongoing disease.     

Large-scale in vitro expansion of polyclonal human CD4(+)CD25high regulatory T cells

CD4(+)CD25+ regulatory T (Treg) cells are pivotal for the maintenance of self-tolerance, and their adoptive transfer gives protection from autoimmune diseases and pathogenic alloresponses after solid organ or bone marrow transplantation in murine model systems. In vitro, human CD4(+)CD25+ Treg cells display phenotypic and functional characteristics similar to those of murine CD4(+)CD25+ Treg cells: namely, hyporesponsiveness to T-cell receptor (TCR) stimulation and suppression of CD25- T cells. Thus far, the detailed characterization and potential clinical application of human CD4(+)CD25+ Treg cells have been hampered by their paucity in peripheral blood and the lack of appropriate expansion protocols. Here we describe the up to 40 000-fold expansion of highly purified human CD4(+)CD25high T cells in vitro through the use of artificial antigen-presenting cells for repeated stimulation via CD3 and CD28 in the presence of high-dose interleukin 2 (IL-2). Expanded CD4(+)CD25high T cells were polyclonal, maintained their phenotype, exceeded the suppressive activity of freshly isolated CD4(+)CD25high T cells, and maintained expression of the lymph node homing receptors L-selectin (CD62L) and CCR7. The ability to rapidly expand human CD4(+)CD25high Treg cells on a large scale will not only facilitate their further exploration but also accelerate their potential clinical application in T cell-mediated diseases and transplantation medicine.     

The immunosuppressive drug FK778 induces regulatory activity in stimulated human CD4+ CD25- T cells

The induction of transplantation tolerance involves a T-cell-mediated process of immune regulation. In clinical transplantation, the use of immunosuppressive drugs that promote or facilitate this process would be highly desirable. Here, we investigated the tolerance-promoting potential of the immunosuppressive drug FK778, currently under development for clinical therapy. Using a human allogeneic in vitro model we showed that, upon T-cell receptor (TCR) triggering, FK778 induced a regulatory phenotype in CD4+ CD25- T cells. Purified CD4+ CD25- T cells primed in the presence of FK778 showed hyporesponsiveness upon restimulation with alloantigen in the absence of the drug. This anergic state was reversible by exogenous interleukin-2 (IL-2) and was induced independent of naturally occurring CD4+ CD25+ regulatory T cells. Pyrimidine restriction was a crucial requirement for the de novo induction of regulatory activity by FK778. The FK778-induced anergic cells showed suppressor activity in a cell-cell contact-dependent manner; were CD25(high), CD45RO+, CD27-, and CD62L-; and expressed cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), glucocorticoid-induced tumor necrosis factor receptor (GITR), and FoxP3. The cells revealed delayed p27(kip1) degradation and enhanced phosphorylation of STAT3. In conclusion, the new drug FK778 shows tolerizing potential through the induction of a regulatory T-cell subset in CD4+ CD25- T cells.     

Expression of CD30 in patients with acute graft-versus-host disease

Acute GVHD (aGVHD) remains a major source of morbidity after allogeneic hematopoietic cell transplantation. CD30 is a cell-surface protein expressed on certain activated T cells. We analyzed CD30 expression on peripheral blood T-cell subsets and soluble CD30 levels in 26 patients at the time of presentation of aGVHD, before the initiation of treatment, compared with 27 patients after hematopoietic cell transplantation without aGVHD (NONE). Analysis by flow cytometry showed that patients with aGVHD had a greater percentage of CD30 expressing CD8(+) T cells with the difference especially pronounced in the central memory subset (CD8(+)CD45RO(+)CD62L(+)): GVHD median 12.4% (range, 0.8%-33.4%) versus NONE 2.1% (0.7%, 17.5%), P < .001. There were similar levels of CD30 expression in naive T cells, CD4(+) T cells, and regulatory (CD4(+)CD127(low)CD25(+)) T cells. Plasma levels of soluble CD30 were significantly greater in patients with GVHD: median 61.7 ng/mL (range, 9.8-357.1 ng/mL) versus 17.4 (range, 3.7-142.4 ng/mL) in NONE (P < .001). Immunohistochemical analysis of affected intestinal tissue showed many CD30(+) infiltrating lymphocytes present. These results suggest that CD30 expression on CD8(+) T-cell subsets or plasma levels of soluble CD30 may be a potential biomarker for aGVHD. CD30 may also represent a target for novel therapeutic approaches for aGVHD.     

In vitro-expanded donor alloantigen-specific CD4+CD25+ regulatory T cells promote experimental transplantation tolerance

CD4+CD25+ regulatory T (Treg) cells play a critical role in the induction and maintenance of peripheral immune tolerance. In experimental transplantation models in which tolerance was induced, donor-specific Treg cells could be identified that were capable of transferring the tolerant state to naive animals. Furthermore, these cells appeared to have indirect allospecificity for donor antigens. Here we show that in vivo alloresponses can be regulated by donor alloantigen-specific Treg cells selected and expanded in vitro. Using autologous dendritic cells pulsed with an allopeptide from H2-Kb, we generated and expanded T-cell lines from purified Treg cells of CBA mice (H2k). Compared with fresh Treg cells, the cell lines maintained their characteristic phenotype, suppressive function, and homing capacities in vivo. When cotransferred with naive CD4+CD25- effector T cells after thymectomy and T-cell depletion in CBA mice that received CBK (H2k+Kb) skin grafts, the expanded Treg cells preferentially accumulated in the graft-draining lymph nodes and within the graft while preventing CBK but not third-party B10.A (H2k+Dd) skin graft rejection. In wild-type CBA, these donor-specific Treg cells significantly delayed CBK skin graft rejection without any other immunosuppression. Taken together, these data suggest that in vitro-generated tailored Treg cells could be considered a therapeutic tool to promote donor-specific transplant tolerance.     

Diversity of regulatory CD4+T cells controlling distinct organ-specific autoimmune diseases

Depletion of selected regulatory CD4+ T cell subsets induces the spontaneous onset of various immune or autoimmune disorders. It is not clear, however, whether a given subset, notably CD4+CD25+ regulatory T cells, protects from a wide spectrum of immune disorders, or whether specialized subsets of regulatory T cells control each given disease or group of diseases. We report here, using diabetes prone nonobese diabetic (NOD) mice, that depending on the regulatory T cells that are depleted, i.e., CD25+, CD62L+, or CD45RB(low), distinct immune diseases appear after transfer into NOD severe combined immunodeficiency (SCID) recipients. Thus, reconstitution of NOD SCID mice with CD25- T cells induces major gastritis and late-onset diabetes, but no or mild colitis. Reconstitution with CD62L- T cells induces fulminant diabetes with no colitis or gastritis. Reconstitution with CD45RB(high) T cells induces major colitis with wasting disease and no or very moderate gastritis and diabetes. Major differences among the three regulatory T cell subsets are also seen in vitro. The bulk of suppressor cells inhibiting the proliferation of CD4+CD25- T cells in coculture is concentrated within the CD25+ but not the CD62L+ or CD45RB(low) T cell subsets. Similarly, cytokine production patterns are significantly different for each regulatory T cell subset. Collectively, these data point to the diversity and organ selectivity of regulatory T cells controlling distinct autoimmune diseases whatever the underlying mechanisms.     

供者CD4＋CD25＋CD127-调节性T细胞与儿童异基因造血干细胞移植后急性移植物抗宿主病相关研究

目的：探讨供体移植物CD4＋CD25＋CDl27-调节性T细胞（_rreg细胞）表达水平对儿童异基因造血干细胞移植（allo—HSCT）后急性移植物抗宿主病（aGVHD）的影响。方法：采用流式细胞术检测供体淋巴细胞中CD4＋CD25＋CDl27-Treg细胞比例,回顾性分析83例allo—HSCT患儿移植物Treg细胞与移植后aGVHD．其中50例恶性疾病．33例良性疾病。结果：83例患儿allo．HSCT均获造血重建,其中51例发生O～Ⅰ度aGVHD,32例发生Ⅱ-Ⅳ度aGVHD。发生0～Ⅰ度aGVHD与Ⅱ-Ⅳ度aGVHD患儿移植物Treg细胞比例有统计学差异（3．0％-＋0．8％比2．5％±1．O％,P=0．030）。中位随访时间286（69～496）d,50例恶性疾病患儿中8例复发,复发与非复发患儿移植物Treg细胞无显著差异（3．2％±0．8％比2．8％±0．8％,P=0．549）。结论：高水平供体移植物Treg细胞有助于降低儿童all0．HSCT后aGVHD发生率,且未增加移植后复发风险;移植物Treg细胞表达量对预测aGVHD有一定意义。     

Efficient generation of human alloantigen-specific CD4+ regulatory T cells from naive precursors by CD40-activated B cells

CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg) play an important role in the induction and maintenance of immune tolerance. Although adoptive transfer of bulk populations of Treg can prevent or treat T cell-mediated inflammatory diseases and transplant allograft rejection in animal models, optimal Treg immunotherapy in humans would ideally use antigen-specific rather than polyclonal Treg for greater specificity of regulation and avoidance of general suppression. However, no robust approaches have been reported for the generation of human antigen-specific Treg at a practical scale for clinical use. Here, we report a simple and cost-effective novel method to rapidly induce and expand large numbers of functional human alloantigen-specific Treg from antigenically naive precursors in vitro using allogeneic nontransformed B cells as stimulators. By this approach naive CD4(+)CD25(-) T cells could be expanded 8-fold into alloantigen-specific Treg after 3 weeks of culture without any exogenous cytokines. The induced alloantigen-specific Treg were CD45RO(+)CCR7(-) memory cells, and had a CD4(high), CD25(+), Foxp3(+), and CD62L (L-selectin)(+) phenotype. Although these CD4(high)CD25(+)Foxp3(+) alloantigen-specific Treg had no cytotoxic capacity, their suppressive function was cell-cell contact dependent and partially relied on cytotoxic T lymphocyte antigen-4 expression. This approach may accelerate the clinical application of Treg-based immunotherapy in transplantation and autoimmune diseases.     

CCR6 expression defines regulatory effector/memory-like cells within the CD25(+)CD4+ T-cell subset

Regulatory CD25(+)CD4+ T cells (Treg cells) are a central element of peripheral tolerance. Little is known, however, about phenotypic and functional characteristics of these cells with regard to memory. In this study we show that the chemokine receptor CCR6 is expressed on a distinct subset of mouse Treg cells. Similar to their CD25- counterparts, CCR6+ Treg cells exhibit markers of activation, memory, and expansion that are indicative for an effector-memory function. They are memory-like cells, generated in vivo from CCR6(-)CD25+ T cells after the encounter of antigen. As conventional CD25- effector-memory T cells, they have a high turnover rate and, in contrast to CCR6- Treg cells, they respond rapidly to restimulation in vitro with up-regulation of interleukin 10. CCR6+ Treg cells are enriched in the peripheral blood and accumulate in the central nervous system after induction of experimental autoimmune encephalomyelitis (EAE). This subset therefore seems to represent a population of regulatory effector-memory T cells (T(REM)), destined to control potentially destructive immune responses directly in inflamed tissues. Importantly, these cells are also present in humans. Here the expression of CCR6 fully cosegregates with CD45RO, an established marker of human memory T cells.     

CD4+CD25+T细胞延长同种异体胰岛移植物存活

探讨CD4+ CD25+调节性T细胞作为细胞疫苗抑制小鼠同种异体胰岛移植物排斥反应的作用,采用免疫磁珠分离技术分选CD4+ CD25+调节性T细胞联合BALB/cByJ小鼠同种异体胰岛移植.结果 显示,CD4+ CD25+调节性T细胞可明显延长同种异体移植物的存活时间.     

CD4+CD25+调节性T细胞及其与移植物抗宿主病和移植物抗白血病的关系

CD4 CD25 调节性T细胞(Treg细胞)是CD4 T细胞的一个亚群,在维持机体自身免疫耐受,诱导移植耐受等方面发挥重要作用。移植物抗宿主病(GVHD)是异基因造血干细胞移植最严重的并发症之一。在动物骨髓移植模型中证实Treg细胞可以促进移植物植入,减少GVHD的发生率和严重度,但并没有消除移植物抗白血病(GVL)的作用。在人体有关Treg细胞对GVHD的影响因研究者分析Treg细胞采用的表型不同,其结论存在不一致性。本文就新近Treg细胞生物学特性,Treg细胞与GVHD和GVL的关系的研究进展进行综述。     

CD4~+ CD25~+调节性T细胞与恶性腹水的相关研究进展

CD4+ CD25+调节性T细胞(CD4+ CD25+Treg细胞)是具有独特免疫调节功能的T细胞亚群,抑制免疫反应,在机体免疫稳态维持、肿瘤免疫及移植耐受等方面发挥重要的作用。近年来,调节性T细胞在肿瘤免疫及治疗的研究中受到越来越广泛的关注。现就调节性T细胞在恶性腹水方面的研究做一简要综述。     

Evidence for naive T-cell repopulation despite thymus irradiation after autologous transplantation in adults with multiple myeloma: role of ex vivo CD34+ selection and age

Immunodeficiency following autologous CD34+-purified peripheral blood stem cell (PBSC) transplantation could be related to T-cell depletion of the graft or impaired T-cell reconstitution due to thymus irradiation. Aiming to assess the role of irradiated thymus in T-cell repopulation, we studied 32 adults with multiple myeloma, randomly assigned to receive high-dose therapy including total body irradiation (TBI) followed by autologous transplantation with either unselected or CD34+-selected PBSCs. The median number of reinfused CD3+ cells was lower in the selected group (0.03 versus 14 x 10(6)/kg; P =.002). Lymphocyte subset counts were evaluated from month 3 to 24 after grafting. Naive CD4+ T cells were characterized both by phenotype and by quantification of T-cell receptor rearrangement excision circles (TRECs). The reconstitution of CD3+ and CD4+ T cells was significantly delayed in the CD34+-selected group, but eventually led to counts similar to those found in the unselected group after month 12. Mechanism of reconstitution differed, however, between both groups. Indeed, a marked increase in the naive CD62L+CD45RA+CD4+ subset was observed in the selected group, but not in the unselected group in which half of the CD45RA+CD4+ T cells appear to be CD62L-. Age was identified as an independent adverse factor for CD4+ and CD62L+CD45RA+CD4+ T-cell reconstitution. Our results provide evidence that infusing PBSCs depleted of T cells after TBI in adults delays T-cell reconstitution but accelerates thymic regeneration.     

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.     

CD4+CD25+ T cells regulate colonic localization of CD4 T cells reactive to a microbial antigen

BACKGROUND: In patients with inflammatory bowel diseases, T-cell activation driven by microflora has been implicated as a mechanism causing clonal expansion and infiltration of CD4+ T cells in colonic lamina propria (LP). We explored a regulatory mechanism preventing infiltration of CD4+ T cells specific to a microbe-associated antigen in the gut. METHODS: SCID mice were reconstituted with CD4+ T cells specific to ovalbumin (OVA) and were orally administered with Escherichia coli engineered to produce OVA. RESULTS: OVA-specific CD4+ T cells (KJ1-26+) were recruited to colonic LP in an Ag-dependent manner, which was inhibited by adoptive transfer of naturally occurring CD4+CD25+ T (Treg) cells. KJ1-26+ T cells and Treg cells are localized preferentially to the colonic follicles that contain dendritic cells. In mice given Treg cells, LP CD4+ T cells showed a decrease in proliferative and interferon gamma response and an increase in transforming growth factor beta1 response to OVA stimulation. Treg cells inhibited both antigenic activation of effector CD4+ T cells and class II/CD80/CD86 up-regulation of dendritic cells. CONCLUSION:: Treg cells suppress recruitment of CD4+ T cells specific to a microbe-associated antigen to LP, which was associated with colocalization of effector CD4+ T cells and Treg cells in colonic follicles.     

慢性乙型肝炎患者浆样树突状细胞体外诱导CD4+CD25+调节性T细胞的研究

目的 观察慢性乙型肝炎患者,乙型肝炎恢复者和健康人浆样树突状细胞(pDCs)体外诱导CD4+CD25+调节性T细胞(CD4+CD25+Treg)能力的差异,为阐明HBV感染慢性化的机制奠定基础.方法 采用免疫磁珠分离法体外分离46例慢性乙型肝炎患者,10例乙型肝炎恢复者和25名健康人外周血单个核细胞中pDCs,并将其分别与健康人CD4+CD45RA+初始T细胞共培养.采用HBcAg或破伤风毒素对去除CD25+细胞的外周血单个核细胞进行增殖刺激后,使用流式细胞仪及RT-PCR对pDCs-T共培养细胞中CD4+CD25+Treg的数量、表型及FOXP3基因表达情况进行测定;采用酶联免疫吸附法对共培养细胞上清液中的白细胞介素-10和转化生长因子β1进行了进一步检测.两组数据比较采用Mann Whitney U-test.结果 当细胞增殖刺激物为HBcAg时,细胞增殖幅度慢性乙型肝炎患者组为(7999.36±374.74)cpm,乙型肝炎恢复者组为(11 282.56±1174.46)cpm和健康人组为(12 304.58±1462.81)cpm,慢性乙型肝炎患者组细胞增殖幅度明显小于乙型肝炎恢复者组和健康人组,U=0～22.0,P值均<0.05·乙型肝炎恢复者组和健康人组间增殖幅度差异无统计学意义.当增殖刺激物为破伤风毒素时,细胞增殖幅度与阳性对照组之间,差异无统计学意义.CD4+CD25+Treg比例慢性乙型肝炎患者组为5.99%±1.85%,乙型肝炎恢复者组为3.04%±0.79%,健康人组为3.01%±1.53%,慢性乙型肝炎患者组中韵CD4+CD25+Treg比例明显高于乙型肝炎恢复者组和健康人组,U=6.0～71.5,P值均<0.05.3组人群pDCs-T共培养细胞的CD4+CD25+T细胞均检测到Fox p3 RNA,而在CD4+CD25 T细胞中,均未检测到Fox p3RNA.3组人群pDCs-T共培养细胞实验组上清液的白细胞介素-10和转化生长因子β1含量均明显高于阳性对照组.结论 pDCs以诱导CD4+CD25+Treg形式参与了乙型肝炎的慢性化.     

Expression of TNFalpha by CD3+ and F4/80+ cells following irradiation preconditioning and allogeneic spleen cell transplantation

The pathogenesis of acute graft-versus-host disease (aGVHD) includes tumor necrosis factor-alpha (TNFalpha) expression by macrophages and T cells. However, the temporal comparison of donor vs host cells to TNFalpha expression in response to irradiation conditioning and alloreactivity has not been reported. This study compared intracellular TNFalpha expression in donor vs host spleen T cells and macrophages using a murine model of aGVHD. Total body irradiation conditioning alone resulted in increased frequency of F4/80+/TNFalpha+ cells, but no increase in CD3+/TNFalpha+ cells. Syngeneic transplantation resulted in an increased frequency of F4/80+/TNFalpha+ cells, while CD3+/TNFalpha+ cells increased on days 1 and 3 but declined on day 5. Allogeneic transplantation resulted in an increased frequency of donor CD3+/TNFalpha+ cells, while the frequency of host CD3+/TNFalpha+ cells declined. Similarly, donor F4/80+/TNFalpha+ cells also increased in frequency after allotransplantation, while the frequency of host F4/80+/TNFalpha+ cells was increased on day 1 and declined through days 3 and 5. In absolute cell numbers, CD3+/TNFalpha+ cells were greater than F4/80+/TNFalpha+ cells post allotransplantation. We conclude that (1) both donor and host CD3+ and F4/80+cells are present in the post transplant period and contribute to TNFalpha production and (2) in terms of frequency, the majority of TNFalpha producing cells in the spleen after allogeneic BMT are CD3+.