Ontogeny, function, and peripheral homeostasis of regulatory T cells in the absence of interleukin-7

Mice lacking interleukin-7 (IL-7-/- mice) have no signs of autoimmune disease, contrary to other models of lymphopenia. We investigated whether the absence of disease was due to the fact that IL-7 is dispensable for the ontogeny, function, and homeostasis of regulatory CD4+ T cells. We show here that the establishment of the peripheral pool of Foxp3-expressing regulatory cells is IL-7 independent, and the premature involution of the thymus in IL-7-/- mice does not change the representation of the CD4+CD25+ T-cell compartment. In addition, CD4+CD25+ T cells expand in the absence of IL-7, without losing Foxp3 expression. The frequency of activated peripheral CD4+ T cells increases with age in both the CD25- and CD25+ compartments, with the CD4+CD25+ T cells displaying signs of constant activation. IL-7-/- CD4+CD25+ T cells control inflammatory bowel disease induced by IL-7-/- T cells even in hosts lacking IL-7. Depletion of the CD25+ T-cell subset after thymic involution results in a mild form of inflammatory bowel disease (IBD), which resolves concomitantly with the regeneration of this subset. This study shows for the first time that IL-7-/- mice have a robust regulatory Foxp3-expressing CD4+ T-cell compartment that controls T-cell-mediated disease. It also highlights the potential of the regulatory Foxp3-expressing CD4+CD25- T-cell population to restore a functional CD4+CD25+ T-cell compartment through an IL-7-independent pathway.     

Foxp3 expression on normal and leukemic CD4+CD25+ T cells implicated in human T-cell leukemia virus type-1 is inconsistent with Treg cells

Foxp3 is a master gene of Treg cells, a novel subset of CD4⁺ T cells primarily expressing CD25. We describe here different features in Foxp3 expression profile between normal and leukemic CD4⁺CD25⁺ T cells, using peripheral blood samples from healthy controls (HCs), human T-cell leukemia virus type-1 (HTLV-1)-infected asymptomatic carriers (ACs), patients with adult T-cell leukemia (ATL), and various hematopoietic cell lines. The majority of CD4⁺CD25⁺ T cells in HCs were positive for Foxp3, but not all CD4⁺CD25⁺ T cells in ACs were positive, indicating that Foxp3 expression is not always linked to CD25 expression in normal T cells. Leukemic (ATL) T cells constitutively expressing CD25 were characteristic of heterogeneous Foxp3 expression, such as intra- and inter-case heterogeneity in intensity, inconsistency with CD25 expression, and a discrepancy in the mRNA and its protein expression. Surprisingly, a discernible amount of Foxp3 mRNA was detectable even in most cell lines without CD25 expression, a small fraction of which was positive for the Foxp3 proteins. The subcellular localization of Foxp3 in HTLV-1-infected cell lines was mainly cytoplasmic, different from that of primary ATL cells. These findings indicate that Foxp3 has two facets: essential Treg identity and molecular mimicry secondary to tumorigenesis. Conclusively, Foxp3 in normal T cells, but not mRNA, is basically potent at discriminating a subset of Treg cells from CD25⁺ T-cell populations, whereas the modulation of Foxp3 expression in leukemic T cells could be implicated in oncogenesis and has a potentially useful clinical role.     

Regulatory potential and control of Foxp3 expression in newborn CD4+ T cells

Thymectomy at day 3 after birth leads to autoimmune disease in some genetic backgrounds. Disease is thought to be caused by the lack/paucity of regulatory T cells. We show that 3-day-old mice already contain a significant compartment of Foxp3-expressing CD25(+)CD4(+) splenocytes. Whereas, in adult spleen, the subsets of regulatory T cells (CD25(+) and/or CD103(+)) express high amounts of Foxp3 mRNA, in 3-day-old mice, both thymic and splenic CD25(+)CD4(+) T cell subsets express lower amounts of Foxp3 mRNA, and CD103(+) cells are barely detected. In adult day 3-thymectomized mice, the CD25(+)CD4(+) T cell subset is overrepresented (most of the cells being CD103(+)) and expresses high amounts of Foxp3 mRNA, independent of the development of autoimmune gastritis. These cells control inflammatory bowel disease and the homeostatic expansion of lymphocytes. This study demonstrates that the peripheral immune system of newborn mice is endowed of a remarkable regulatory potential, which develops considerably in the absence of thymic supply.     

Expression of the putatively regulatory T-cell marker FOXP3 by CD4(+)CD25+ T cells after pediatric hematopoietic stem cell transplantation

FOXP3 has been proposed to be critical for the regulatory function of CD4(+)CD25+ T cells and it has been reported that its expression correlates with protection from graft-versus-host-disease (GvHD) after allogeneic hematopoietic stem cell transplantation (HSCT). Here, by monitoring 28 pediatric HSCT recipients, we found that the levels of FOXP3-mRNA expression in highly enriched CD4(+)CD25+ cells were identical to those in healthy controls irrespective of GvHD status. Moreover, FOXP3-mRNA was abundant in recently in vitro stimulated CD4(+)CD25+ cells that lacked regulatory function. Together these findings suggest that FOXP3-mRNA expression primarily reflects CD4(+)CD25+ cell frequency rather than defining the regulatory potential of CD4(+)CD25+ T cells and GvHD risk after HSCT.     

CD4+CD25+Foxp3+调节性T细胞在慢性乙型肝炎患者中的作用

目的 探讨CD4+CD25+Foxp3+调节性T细胞与乙型肝炎慢性化和病毒清除之间的关系.方法 收集慢性活动性乙型肝炎(CAH)患者19例、HBV携带者(AsC)21例、HBV感染恢复者12例和健康对照者15例.通过流式细胞术分析外周血CD4+CD25+Foxp3+T细胞的表型和频率,磁珠分选(MACS)CD4+CD25+T细胞,实时荧光定量PCR方法 分析Foxp3 mRNA基因在CD4+CD25+T细胞的表达水平.统计学处理采用单因素方差分析或非参数检验.结果CAH或AsC组外周血CD4+CD25+Foxp3+T细胞频率以及CD4+CD25+T细胞中Foxp3 mRNA的表达水平显著高于健康对照组或HBV感染恢复者(F=6.8,F=3.72,均P<0.05).免疫组织化学染色发现,CAH患者肝组织Foxp3'T细胞浸润累积较对照组明显增高,但AsC较CAH减少.HBeAg阳性患者(包括CAH和AsC)CD4'CD25'T细胞频率显著高于HBeAg阴性患者(t=2.3,P<0.05),抗-HBe阴性患者显著高于抗-HBe阳性患者(t=2.4,P<0.05).CD4+CD25+Foxp3+T细胞频率与慢性乙型肝炎患者血清中HBV病毒载量存在正相关(r=0.56,P<0.01).结论 慢性乙型肝炎患者CD4+CD25+Foxp3+调节性T细胞异常与乙型肝炎慢性化和病毒清除有关.     

Immune reconstitution after haematopoietic cell transplantation in children: immunophenotype analysis with regard to factors affecting the speed of recovery

Immune reconstitution was studied prospectively in 66 children who underwent 77 haematopoietic cell transplantations (HCT): 46 autologous HCTs in 39 patients and 31 allogeneic HCTs in 27 patients. We studied the dynamic analysis of immune recovery with regard to potential factors affecting its speed, including age, type of HCT, diagnosis, graft-versus-host disease (GvHD) and cytomegalovirus (CMV) infection reactivation. Absolute counts of different lymphocyte subsets and immunoglobulin serum levels were determined in peripheral blood of patients on d -7 and +16, and then at various intervals up to 24 months post transplant. Common patterns of immune recovery after both allogeneic and autologous HCT were identified: (i) CD4+CD45RO+ peripheral T-cell expansion on d +16; (ii) inverted CD4+:CD8+ ratio from d +30 onwards; (iii) rapid natural killer (NK) cell (CD16+/-CD56+) count normalization. We observed prolonged T-cell lymphopenia (CD3+, CD3+CD4+, CD4+CD45RA+) until 24 months after autologous HCT, whereas in the allogeneic setting CD3+CD4+ cells, including naive CD45RA+ cells, returned to normal values at 9 months post transplant. Age > 10 years and coexistence of GvHD and CMV reactivation were associated with a substantial delay in T- (CD4+, including CD45RA+) and B-cell recovery after allogeneic HCT. Multidrug GvHD prophylaxis resulted in impaired T- (CD4+, CD4+CD45RA+) and B-cell reconstitution only in the early phase after allogeneic HCT (up to 4 months). Our results demonstrated that T-cell recovery was severely impaired in children after autologous HCT. It should be emphasized that specific approaches to enhance immune reconstitution are necessary to control minimal residual disease and avoid the risk of infectious complications in the autologous setting. Thymic involution after allogeneic HCT seems to be associated with age and coexistence of GvHD and CMV reactivation.     

A possible role for CCL27/CTACK-CCR10 interaction in recruiting CD4 T cells to skin in human graft-versus-host disease

Graft-versus-host disease (GvHD) is a serious complication of allogeneic stem cell transplantation (SCT) affecting the skin, gut and liver. The involvement of distinct organs suggests a role for tissue-specific chemokines and their receptors in directing activated donor T cells to these sites. In this study the potential involvement of the skin-specific CCL27/CTACK-CCR10 interaction was investigated in 15 paediatric SCT patients with skin GvHD. During the course of skin GvHD, peripheral blood T cells from these patients contained a high proportion of CD4+ CCR10+ T cells that disappeared after the GvHD was resolved. These cells were CD45RO+, expressed additional skin homing markers (cutaneous lymphocyte-associated antigen and CCR4), and produced the T-cell helper type 1-cytokines tumour necrosis factor-alpha and interleukin-2. The increase in CD4+ CCR10+ T cells was absent in SCT patients without GvHD. Immunohistochemical investigations showed CD4+ CCR10+ T cells in the GvHD skin biopsies of the same patients, but not in the gut biopsies of patients also suffering from gut GvHD. The infiltration of CD4+ CCR10+ T cells in the GvHD-affected skin correlated with an enhanced epidermal expression of CCL27/CTACK, the ligand for CCR10. These findings support the involvement of CCL27/CTACK-CCR10 interaction in recruiting CD4+ T cells to the skin, thus contributing to the pathogenesis of acute GvHD.     

Expansion of natural killer cell receptor (CD94/NKG2A)-expressing cytolytic CD8 T cells and CD4+CD25+ regulatory T cells from the same cord blood unit

OBJECTIVE: Cord blood contains a significant number of precursor cells that differentiate to cytotoxic effector cells and immunoregulatory cells. We tried to expand inhibitory natural killer cell receptor CD94-expressing CD8 T cells with cytolytic activity and CD4(+)CD25(+) regulatory T cells from the same cord cell unit. METHODS: Cytotoxic CD94-expressing CD8 T cells were expanded from CD4-depleted cord blood using an immobilized anti-CD3 monoclonal antibody and a cytokine and also CD4(+)CD25(+) regulatory T cells were expanded from a CD4-enriched fraction derived from the same cord blood unit using anti-CD3/CD28 monoclonal antibody-coated Dynabeads and cytokines. RESULTS: We were able to obtain a more than 1000-fold expansion of CD94-expressing CD8 T cells and a more than 50-fold expansion of CD4(+)CD25(+) cells from the same cord blood unit. These expanded CD4(+)CD25(+) cells expressed FoxP3 mRNA at a level about 100-fold higher than that in isolated CD25(-) cells and could suppress allogeneic mixed lymphocyte culture by >80% (effector cells: CD4(+)CD25(+) cells = 2:1). Cytolytic activities of purified CD94-expressing cells detected by a 4-hour (51)Cr release assay against K562 were >60%. Coculture of CD94-expressing cells with expanded CD4(+)CD25(+) cells did not have any effect on cytolytic activities of purified CD94-expressing cells against K562 cells. CONCLUSION: These expanded cytolytic CD94-expressing CD8 cells might be able to induce a graft-vs-leukemia effect without enhancing graft-vs-host disease, and CD4(+)CD25(+) cells might be able to suppress allogeneic responses, including graft-vs-host disease and graft rejection after cord blood transplantation.     

Foxp3+ CD25- CD4 T cells constitute a reservoir of committed regulatory cells that regain CD25 expression upon homeostatic expansion

Expression of the IL-2 receptor alpha chain (CD25) by peripheral CD4 T cells follows cellular activation. However, CD25 expression by CD4 cells is widely used as a marker to identify regulatory T cells (T(R)), although cells with regulatory properties are also found in the CD4+CD25- subset. By using in vivo functional assays and Foxp3 expression as a faithful marker of T(R) differentiation, we have evaluated the requirements for CD25 expression by peripheral T(R). We first show that in vivo depletion of CD25+ cells prevents the development of spontaneous encephalomyelitis in recombination-activating gene (RAG)-deficient anti-myelin basic protein T cell antigen receptor (TCR) transgenic mice, and allows disease induction in otherwise healthy RAG-competent transgenic mice. Similar treatment in normal thymectomized animals is followed by the fast recovery of a normal number of CD25+ T(R). Consistently, Foxp3-expressing T(R) encompassed in the CD25- cell population convert to CD25+ after homeostatic expansion and are selectable by IL-2 in vitro. Surface expression of CD25 on T(R) is controlled by the activity of conventional CD4 cells and is fully labile because it can be lost and regained without affecting the functional potential of the cells. These findings reveal that Foxp3-expressing CD25- cells constitute a peripheral reservoir of differentiated T(R), recruited to the CD25+ pool upon homeostatic expansion and/or activation. This analysis, together with the notion that physiological commitment of T(R) takes place exclusively in the thymus should help for the interpretation of experiments assessing peripheral T(R) differentiation from naive CD4 T cells, defined as CD25-.     

Depletion of Thymus-Derived CD4+CD25+ T Cells Abrogates the Suppressive Effects of alpha-galactosylceramide Treatment on Experimental Allergic Conjunctivitis.

Background: We showed previously that alpha-galactosylceramide (alpha-GalCer) treatment elevated splenic CD4+CD25+Foxp3+ T-cell numbers and suppressed the development of experimental allergic conjunctivitis (EC). Here, we investigated whether CD4+CD25+Foxp3+ T cells mediate the suppressive effects of alpha-GalCer treatment on EC. Methods: To deplete CD4+CD25+Foxp3+ T cells, neonatal mice were thymectomized and intraperitoneally injected with anti-CD25 Ab. At 6 weeks of age, these mice were immunized with ragweed (RW) in aluminum hydroxide. Ten days later, the mice were challenged with RW in eye drops and 24 hours later, the conjunctivas and spleens were harvested for histological and flow cytometric analyses, respectively. alpha-GalCer or vehicle was injected 2 hours prior to RW challenge. In addition, alpha-GalCer was injected into thymus-intact EC-developing mice that had not been treated with anti-CD25 Ab. Results: alpha-GalCer treatment significantly suppressed EC in the thymus-intact mice that had not been treated with anti-CD25 Ab. In contrast, alpha-GalCer treatment of thymectomized and anti-CD25 Ab-treated mice did not affect the severity of EC or splenic CD4+CD25+Foxp3+ T-cell numbers. However, alpha-GalCer treatment did significantly increase splenic CD4+CD25+Foxp3+ T-cell numbers in thymectomized mice that had not received anti-CD25 Ab. Conclusions: alpha-GalCer treatment during the effector phase of EC increased CD4+CD25+Foxp3+ T-cell numbers, which in turn suppressed the development of EC.     

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.     

CD70+ non-Hodgkin lymphoma B cells induce Foxp3 expression and regulatory function in intratumoral CD4+CD25 T cells

Foxp3 expression was initially thought to be restricted to the CD4(+)CD25(+) regulatory T-cell population. However, recent studies suggest that forkhead box P3 (Foxp3) is expressed in CD4(+)CD25(-) T cells in aged mice. In the present study in B-cell non-Hodgkin lymphoma (NHL), we found that a subset of intratumoral but not peripheral blood CD4(+)CD25(-) T cells, comprising about 15% of intratumoral CD4(+) T cells, express Foxp3 and are capable of suppressing the proliferation of autologous infiltrating CD8(+) T cells. In vitro activation with OKT3/anti-CD28 antibody (Ab) or dendritic cells (DCs) induced Foxp3 expression in a subset of these CD4(+)CD25(-)Foxp3(-) T cells. We found that the presence of lymphoma B cells during activation augmented activation-induced Foxp3 expression in CD4(+)CD25(-) T cells. We also found that CD70(+) lymphoma B cells significantly contributed to the activation-induced Foxp3 expression in intratumoral CD4(+)CD25(-) T cells. Furthermore, the blockade of CD27-CD70 interaction by anti-CD70 Ab abrogated lymphoma B-cell-mediated induction of Foxp3 expression in intratumoral CD4(+)CD25(-) T cells. Taken together, these studies reveal a novel role for NHL B cells in the development of intratumoral regulatory T cells.     

间充质干细胞对系统性红斑狼疮CD4+Foxp3+T淋巴细胞的调节

目的 探讨同种异体骨髓间充质干细胞(MSC)体内外对系统性红斑狼疮(SLE)患者外周血CD4+Foxp3+T淋巴细胞及人脐带MSC移植对MRL/lpr鼠脾脏和淋巴结CD4+Foxp3+T淋巴细胞水平的影响.方法 血缘相关供者骨髓中分离培养MSC移植治疗5例SLE患者,采用流式细胞术检测移植前后外周血CD4+Foxp3+T淋巴细胞百分率.7例SLE患者外周血单个核细胞(PBMC)分别与SLE患者和正常人骨髓MSC按不同比例体外共培养72 h,检测共培养后PBMC中CD4+Foxp3+T淋巴细胞百分率.MRL/Ipr鼠输注脐带MSC后检测脾脏和淋巴结CD4+Foxp3+T淋巴细胞百分率.结果 SLE患者异基因骨髓MSC移植后1周外周血CD4+Foxp3+T淋巴细胞百分率(4.8±1.6)%和移植后3个月(6.0±2.6)%均较移植前(2.1±1.2)%明显升高(5例,P<0.05).正常骨髓MSC与SLE患者PBMC共培养后CD4+Foxp3+T淋巴细胞百分率明显升高(P<0.05).且存在剂量依赖性,狼疮MSC也可上调SLE患者CD4+Foxp3+T淋巴细胞水平,但作用较正常MSC弱(P<0.05);正常MSC培养上清也可上调SLE患者PBMC中CD4+Foxp3+T淋巴细胞水平,但作用弱于MSC:PBMC=1:1组(P<0.05).MRL/Ipr鼠经1次或3次脐带MSC移植后脾脏CD4+Foxp3+T淋巴细胞百分率均较对照组高(P<0.05),但淋巴结CD+Foxp3+T淋巴细胞百分率均较对照组低(p<0.01),1次和3次移植组间差异无统计学意义.结论 异基因甚至异种MSC移植可上调SLE患者或MRL/Ipr鼠CD4+Foxp3+T淋巴细胞水平,同时体外试验也得出相同结论,且体外上调作用呈一定剂量依赖性,CD4+Foxp3+T淋巴细胞水平上调可能是MSC移植治疗SLE有效的机制之一.     

CD4+CD25+Foxp3+调节性T细胞在不同月龄小鼠中的变化及与肺癌关系

目的 探讨CD4+CD25+Foxp3+调节性T(Treg)细胞在衰老过程中的变化及与肺癌的关系.方法 建立Lewis肺癌模型,36只C57BL/6小鼠分成6组,青年健康组、中年健康组、老年健康组以及青年肿瘤组、中年肿瘤组、老年肿瘤组.通过流式细胞分析法测定6组小鼠脾脏细胞中CD4+CD25+Foxp3+Treg占CD4+T细胞的百分比来反映CD4+CD25+Foxp3+Treg细胞含量,通过实时荧光定量PCR法测定Foxp3mRNA的含量.结果 与健康组相比,肺肿瘤鼠脾脏中CD4+CD25+Foxp3+/CD4+T细胞和Foxp3 mRNA的含量明显增高(均P＜0.05);在健康组内,各年龄段CD4+CD25+Foxp3+/CD4+T细胞(F=47.70,P=0.000)和Foxp3mRNA(F=6.56,P=0.009)差异有统计学意义,老年鼠脾脏细胞中含有高数量的CD4+CD25+Foxp3+Treg细胞和Foxp3mRNA,最高组是老年肺肿瘤鼠.结论 CD4+CD25+Foxp3+Treg细胞和其功能基因Foxp3含量的改变与增龄和肺肿瘤的发生和发展存在密切的关系.

Abstract：

Objective To explore the change of CD4+CD25+Foxp3+ regulatory T (Treg) cells during aging and the relation with lung tumor. Methods The Lewis lung cancer model was set up in C57BL/6 female mice, and the 36 mice were divided into young health group, middle-aged health group, elderly health group, young tumor group, middle-aged tumor group and elderly tumor group. The percentages of CD4+CD25+Foxp3+ Treg in CD4+ T cells in mice spleen cells were measured by flow cytometry, for reflecting the quantity of CD4+CD25+Foxp3+ Treg cells. And the level of Foxp3 mRNA in splenocyte was tested by real-time PCR method. Results The level of CD4+CD25+Foxp3+/CD4+ T cells and the quantity of Foxp3 mRNA were higher in tumor groups than in healthy groups(both P＜0.05 ). Besides, in the healthy groups, there were statistical differences in the level of CD4+CD25+Foxp3+/CD4+ T cells (F=47.70, P=0.000) and the quantity of Foxp3 mRNA among the different months groups. Accumulation of the CD4+CD25+Foxp3+ Treg cells was accompanied with aging, the elderly mice contained a significantly larger population of CD4+CD25+Foxp3+ Treg cells in their spleen when compared with the younger counterparts, and the highest was the elderly tumor group. So it was with the functional gene Foxp3 mRNA (F=6.56, P=0.009). Conclusions The results suggest a close relationship of the change of CD4+CD25+Foxp3+Treg cells with aging and the genesis and development of lung tumor.     

CD4+CD25-Foxp3+T淋巴细胞的表型鉴定及其在初发系统性红斑狼疮中的意义

目的 对初发系统性红斑狼疮(SLE)患者外周血异常表达CD4+CD25-Foxp3+T淋巴细胞进行表型鉴定,并探讨其临床意义.方法 对初发SLE患者外周血CD4+T淋巴细胞进行细胞表面分子[CD25、CD127、CCR4、糖皮质激素诱导的肿瘤坏死因子受体(GITR)、细胞毒T淋巴细胞相关抗原4(CT-LA-4)]和胞内分子(Foxp3)标染,流式细胞仪检测,并研究CD4+各细胞亚群与狼疮肾炎和疾病活动度(SLEDAI)相关性.结果 SLE患者外周血CD4+CD25-Foxp3+T淋巴细胞表面 GITR、CTLA-4和CCR4表达率与活化T淋巴细胞(CD4+CD25+Foxp3-)相比差异无统计学意义(P均>0.05),而显著低于调节性T淋巴细胞(CD4+CD25+Foxp3+)(P均<0.01);CD4+Foxp3+CD25high,CD4+Foxp3+CD25low和CD4+Foxp3+CD25-细胞中CD127low-百分率分别为(93.8±,3.5)%,(93.7±2.3)%,(92.0±2.1)%,三者之间差异无统计学意义(P>0.05);在CD4+细胞亚群中,当CD127low-时,Foxp3+在CD25high,CD25low和CD25-中表达率分别为 (91.4±2.6)%,(71.9±3.3)%,(9.0±2.2)%,三者之间差异均有统计学意义(P<0.01);SLE患者外周血CD4+CCR4+CD25highT淋巴细胞百分率与SLEDAI呈显著负相关(r=-0.695,P<0.001),狼疮肾炎患者(1.10±0.17)%显著低于SLE无肾炎组[(1.61±0.23)%,P<0.01]和健康对照组[(1.75±0.10)%,P<0.01];狼疮肾炎患者外周血CD4+ CCR4+CD25low-T淋巴细胞百分率显著高于健康对照组[(11.5 ±2.3)%与(8.0±1.0)%,P<0.01)].结论 初发SLE中异常升高的CD4+CD25-Foxp3+T淋巴细胞的表型类似早期活化效应T淋巴细胞.可以用CD4+CD25highCD127low-T淋巴细胞替选CD4+CD25highFoxp3+调节性T淋巴细胞.CCR4+调节性T淋巴细胞可能参与狼疮肾炎发病.     

Mucosal FOXP3+ regulatory T cells are numerically deficient in acute and chronic GvHD

CD4+CD25+ regulatory T cells (Tregs) control immune responses to self- and foreign antigens and play a pivotal role in autoimmune diseases, infectious and noninfectious inflammation, and graft rejection. Since recent experimental studies have indicated that Tregs were able to ameliorate graft-versus-host disease (GvHD), we analyzed the number of infiltrating Tregs in the intestinal mucosa as one site of GvH reactivity using immunoenzymatic labeling to enumerate FOXP3+ T cells in 95 intestinal biopsies from 49 allografted patients in comparison with healthy controls and patients with infectious inflammation. While patients with cytomegalovirus (CMV)-colitis or diverticulitis showed a concomitant increase of CD8+ effectors and Tregs, acute and chronic GvHD were characterized by the complete lack of a counter-regulation indicated by a FOXP3+/CD8+ T-cell ratio identical to healthy controls. In contrast, specimens without histologic signs of GvHD demonstrated increased numbers of FOXP3+ per CD8+ T cells, indicating that the potential for Treg expansion is principally maintained in allografted patients. Our findings provide evidence that GvHD is associated with an insufficient up-regulation of Tregs in intestinal GvHD lesions. The determination of FOXP3+/CD8+ ratio can be a helpful tool to discriminate GvHD from infectious inflammation after allogeneic stem cell transplantation.