Mutation and Clinical Feature of IL-7R in Adult Patients with Acute Lymphoblastic Leukemia / 中国实验血液学杂志

OBJECTIVE@#To investigate the IL-7R gene mutation and clinical features of adult patients with acute lymphoblastic leukemia (ALL).@*METHODS@#One hundred sixty-four cases of newly treated adults with ALL from May 2016 to December 2018 were selected. Targeted and specific next-generation sequencing technology was used to detected a total of 16 types of Ph-like ALL mutations, which include IL-7R mutation, and the cilinical features, rate, types and sites of IL-7R were analyzed.@*RESULTS@#IL-7R mutation was determined in 10 cases of 164 adult patients with ALL and the total mutation frequency was 13 times (6.1%). Out of 10 cases 5 cases were male (50%), 5 cases were female (50%). 6 cases of B-ALL ( 60% ) and 4 cases of T-ALL (40%). The mutation site of all cases was located at exon 6, among which 6 cases had replacement mutations, 3 cases had deletion mutations and 4 cases had insertion mutations. In addition, 1 triple and 1 double mutation of IL-7R were found. Besides, six mutation sites were newly identified, including: c.720_724del, c.723_726del, c.721_722insAGTG, c.727_728insTAACGGCCCCCTGCT, c.727_728insATGCAGGGAGCGAA and c.728_729insAAGTGTCA.@*CONCLUSION@#Six novel mutation sites and a poor manifestation of IL-7R have been explored in this research. Thus more samples are required to study the effects of IL-7R mutation on ALL treatment.

Relationship between CD4⁺CD25(High)CD127(low) regularly T cells in the peripheral blood and tumor regression after neoadjuvant therapy in patients with rectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To observe the proportion change of immune cells in the peripheral blood of patients with rectal cancer after neoadjuvant therapy and to explore the relationship between tumor regression and CD4⁺CD25(High)CD127(low) regularly T cells(Treg cells).</p><p><b>METHODS</b>Patients with rectal cancer who underwent the neoadjuvant therapy before surgery at the Shanxi Cancer Hospital Colorectal Surgery Department from January to December 2013 were prospectively enrolled. These patients were divided into down-staging group and non-down-staging group according to the change of staging in accordance with TNM classification for rectal cancer after neoadjuvant therapy. Flow cytometry was used to analyze the proportions of Treg cells, CD4+T cells, CD8+T cells, NK cells, B cells, and CD4+/CD8+ ratio in the peripheral blood from these patients before and after neoadjuvant therapy.</p><p><b>RESULTS</b>A total of 108 patients were enrolled, including 76 cases in the down staging group and 32 cases in the non-down-staging group. Differences of immune cells proportions between two groups before neoadjuvant therapy were not statistically significant(all P>0.05). In the down-staging group, the proportions of Treg cells, B cells and CD4+/CD8+ ratio were decreased while the proportion of NK cells did not change obviously after the neoadjuvant therapy. Interestingly, in the non-down-staging group, the proportions of B cells and CD4+/CD8+ ratio were decreased while the proportions of Treg cells and NK cells did not change obviously after the neoadjuvant therapy. In addition, after neoadjunvat therapy, the proportion of Treg cells in down-staging group was significantly lower than that in non-down-staging group [(4.4 ± 1.7)% vs. (6.2 ± 1.9)%, P=0.001].</p><p><b>CONCLUSION</b>For patients in the down-staging group after neoadjuvant therapy, the proportion of Treg cells in peripheral blood decreases, suggesting that Treg cells may be a valuable biomarker for assessing tumor regression.</p>

A cross-sectional study on the effect of virological response after HAART on subsets of T lymphocytes and expression of CD127 in pediatric AIDS patients with different viral loads / 中华儿科杂志

<p><b>OBJECTIVES</b>To study the effect of HAART on subsets of T lymphocytes and expression of CD127 on memory and naїve CD4(+) and CD8(+)T cells in pediatric AIDS patients with different viral loads receiving HAART.</p><p><b>METHOD</b>A cross- sectional study on 194 pediatric AIDS patients receiving HAART was carried out and 52 age matched healthy children were recruited as controls. The percentage of CD4(+), CD8(+), CD8(+)CD45RA(+)CD127(+/-), CD8(+)CD45RO(+)CD127(+/-), CD4(+)CD45RA(+)CD127(+/-) and CD4(+)CD45RO(+)CD127(+/-)T cells was tested using flow cytometry, and HIV-RNA in plasma was detected by quantitative RT-PCR.</p><p><b>RESULT</b>The percentage of memory (CD45RO(+)) CD4(+)T cells decreased to (45.73 ± 8.85)%, and that of naїve (CD45RA(+)) CD4(+) and memory CD8(+)T increased to (60.44 ± 5.01)% and (54.69 ± 7.71) % respectively in the pediatric AIDS patients vs. controls (P < 0.05). The percentage of naїve (CD45RA(+)) CD4(+)T cells of patients with viral load (VL) < 400 copies/ml was (65.57 ± 5.33) %, which was significantly higher than that of patients with VL ≥ 400 copies/ml (P < 0.05).Of patients with VL < 400 copies/ml, the percentage of CD4(+)CD127(+)T cells, especially the subset of memory CD4(+)CD127(+)T cells was (82.35 ± 2.31)%, which was higher than that of patients with VL ≥ 400 copies/ml, but lower than that of controls (P < 0.05). The percentage of memory and naїve CD8(+)CD127(+)T cells was lower than that of controls (P < 0.05).</p><p><b>CONCLUSION</b>The recovery of CD4(+)T cell subsets in pediatric AIDS patients is associated with viral load. Effective HAART can increase the percentage of naїve CD4(+)T cells and the life of memory CD4(+)T cells.</p>

Changes to CD4(+)CD25(high+)CD127(low) regulatory T cells in peripheral blood from children with bronchiolitis, and its clinical significance / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study changes to CD4(+)CD25(high+)CD127(low) regulatory T cells (Treg) in peripheral blood from children with bronchiolitis, and to explore its clinical significance.</p><p><b>METHODS</b>Thirty-one children with bronchiolitis and aged under two years were randomly enrolled as the bronchiolitis group, and 25 under two-year-olds with bronchopneumonia were randomly enrolled as the bronchopneumonia group. A further twenty-five children with non-infectious diseases such as hernia and renal calculus served as the control group. The level of CD4(+)CD25(high+)CD127(low) Treg in peripheral blood was measured by multi-color detection and multi-parameter flow cytometry.</p><p><b>RESULTS</b>The proportion of CD4(+)CD25(high+)CD127(low) Treg in peripheral blood in the bronchiolitis group (8.0%±2.1%) was significantly lower than in the bronchopneumonia (9.6%±2.6%; P<0.05) and control groups (11.3%±2.9%; P<0.05).</p><p><b>CONCLUSIONS</b>CD4(+)CD25(high+)CD127(low) Treg level in peripheral blood may be an index of immunological function in infants. A decreased level of CD4(+)CD25(high+)CD127(low) Treg in peripheral blood suggests that Treg cells may be involved in the pathogenesis and development of bronchiolitis.</p>

Changes of regulatory T cells and FoxP3 gene expression in the aging process and its relationship with lung tumors in humans and mice / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Immunosuppressive regulatory T cells (Tregs) participate in tumor immune evasion and the number and suppressive function of Tregs change with the aging process, but it is not clear whether such change leads to a higher incidence of tumors in the elderly. To this end, we designed experiments to explore the changes of Tregs and the functional gene Forkhead box P3 (FoxP3) in the aging process and its relationship with lung tumors in humans and mice.</p><p><b>METHODS</b>The percentage of CD4(+)CD25(+)CD127(low) Tregs and expression of FoxP3 mRNA were analyzed using flow cytometry (FCM) and real-time fluorescence-based quantitative polymerase chain reaction (FQ-PCR). Markers were analyzed in the peripheral blood (PB) of 65 elderly patients (age ≥ 65 years) with primary non-small cell lung cancer (NSCLC), 20 younger patients (aged < 55 years) with NSCLC, 30 elderly healthy individuals and 30 young healthy individuals. Furthermore, we set up the Lewis lung cancer model with C57BL/6 female mice. Thirty-six mice were divided into a young healthy group, a middle-aged healthy group, an elderly healthy group, a young tumor group, a middle-aged tumor group, and an elderly tumor group. The percentage of CD4(+)CD25(+)FoxP3(+) Tregs and the expression level of FoxP3 mRNA in splenocytes were determined in the six groups.</p><p><b>RESULTS</b>The percentage of peripheral CD4(+)CD25(+)CD127(low) Tregs and the expression of FoxP3 mRNA were significantly increased in elderly patients with NSCLC comparing with the other groups and in elderly healthy individuals compared with young healthy individuals. Further analysis showed that the percentage of CD4(+)CD25(+)CD127(low) Tregs and the expression of FoxP3 mRNA were closely associated with tumor node metastasis (TNM) staging in elderly patients with NSCLC. In the mouse model, the percentage of CD4(+)CD25(+)FoxP3(+) Tregs and the expression of FoxP3 mRNA in splenocytes of the tumor groups were significantly higher than in the healthy groups, with the highest expression in the elderly tumor group. In the healthy groups, the elderly healthy mice had the highest percentage of Tregs and expression of FoxP3 mRNA. The elderly mice had larger and heavier tumors than did the young and middle aged mice.</p><p><b>CONCLUSIONS</b>The up-regulation of Tregs and the FoxP3 gene with aging may play an essential role in oncogenesis and development of lung tumors in an elderly population.</p>

Analysis of CD4(+)CD25(+)CD127(low/-) Treg cells in mice / 中国实验血液学杂志

The quantitative identification and enrichment of viable regulatory T cells (Treg) requires reliable surface markers that are selectively expressed on Treg. Foxp3 is the accepted marker of natural Treg, but it cannot be used to isolate cells for functional studies. CD127 is a new surface marker expressed in Treg cells. In this study, two populations of Treg, including CD4(+)CD25(+)CD127(low/-) and CD4(+)CD25(+)Foxp3(+)T cells, and profiles of the Foxp3 expression in CD4(+)CD25(+)CD127(low/-) cells were compared to evaluate which population is better. The peripheral blood cells were collected and spleen suspension of BALB/C mice were prepared, and using triple staining CD4, CD25, CD127 and CD4, CD25, Foxp3. The profiles of Treg, including CD4(+)CD25(+)CD127(low/-) and CD4(+)CD25(+)Foxp3(+) were detected by flow cytometry. The quadruple staining CD4, CD25, Foxp3 and CD127 were used to determine the CD127 expression in CD4(+)CD25(+)Foxp3(+) cells. The results showed that on T cell subset the median expression levels of CD4(+), CD4(+)CD25(+) were 39.02%, 5.35% in peripheral blood and 23.49%, 3.86% in spleen. On CD4(+) T cell subset, the median expression level of CD4(+)CD25(+)CD127(low/-) and CD4(+)CD25(+)Foxp3(+)T cells were 7.13%, 3.97% in peripheral blood and 12.8%, 8.23% in spleen. The ratio of CD4(+)CD25(+)CD127(low/-) T cells was higher than that of CD4(+)CD25(+)Foxp3(+) cells in both peripheral blood and spleen cells (P < 0.01). The CD4(+)CD25(+)CD127(low/-) cells highly expressed Foxp3, while the CD4(+)CD25(+)Foxp3(+)T cells lowly expressed CD127. It is concluded that compared with the CD4(+)CD25(+)Foxp3(+) populations, CD4(+)CD25(+)CD127(low/-) T cells better fit the definition of naturally occurring regulatory T cells in peripheral blood cells and spleen of BALB/C mice. CD127(low/-) is a characteristic marker on surface of CD4(+)CD25(+) Treg cells, and has been confirmed to be more specific marker for quantitatively sorting Treg cells.

Loss of CD127 & increased immunosenescence of T cell subsets in HIV infected individuals.

Background & objectives: HIV infection is characterized by a perturbation in T cell homeostasis, leading to alteration in T cell subsets. In addition to alteration in differentiation, HIV infection also leads to change in T cell survival and regenerative capacity, as suggested by differential expression of CD127 and CD57. We evaluated the expression patterns of CD127 and CD57 on CD4 and CD8 effector, memory and naïve T cell subsets in HIV-infected and uninfected individuals. Methods: We characterized T cell subsets based on expression of these markers, and compared their expression pattern in HIV infected subjects and uninfected controls. We further assessed therapy generated changes in these subsets and expression of CD127 and CD57 on them. Results: There was a generalized decrease in naïve CD4 and CD8 T cells in HIV infected subjects. These changes in T cell subset distribution were related to antigen load. CD127 expression was significantly reduced in T cells from HIV infected subject. In association to this, HIV infected subjects had higher percentage of T cell subsets expressing CD57. Increased CD57 and reduced CD127 expression correlated with plasma viraemia and CD8 T cell activation state. Incomplete restoration of T cell subset proportions was observed, despite suppression of viral replication and increase in CD4 T cell counts. Further, the improvement was more pronounced in CD127 expression. Interpretation & conclusions: HIV infected subjects have reduced T cell regenerative capacity along with increased senescence, highlighting decreased proliferation and effector activities.

HLA-DR expression on regulatory T cells is closely associated with the global immune activation in HIV-1 infected subjects naïve to antiretroviral therapy / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The frequencies of regulatory T cells (Tregs) increased over the HIV infection but its counts actually decreased. We proposed that the decrease of Treg counts may cause the reduction of inhibitory effect and thereby account for the over-activation of Tregs during HIV infection. However, it remains unknown whether Tregs are also over-activated and thereafter the activation induced death may lead to the decrease of Tregs.</p><p><b>METHODS</b>Tregs were defined as CD4(+)CD25(+)CD127(lo/-) T cells. Eighty-one HIV-1 infected patients were enrolled in our study, and twenty-two HIV-1 seronegative donors were recruited as the control. The levels of HLA-DR on Tregs were determined by FACSAria flow cytometer.</p><p><b>RESULTS</b>Compared to HIV-1 seronegative donors, the levels of HLA-DR on CD4(+)CD25(+)CD127(lo/-) Tregs were significantly increased in HIV-1 infected patients, and its increase was positively associated with viral loads (r = 0.3163, P = 0.004) and negatively with CD4 T-cell counts (r = -0.4153, P < 0.0001). In addition, significant associations between HLA-DR expression on CD4(+)CD25(+)CD127(lo/-) Tregs and the percentages of HLA-DR, CD38, Ki67 expressing CD4(+) and CD8(+) T cells were also identified.</p><p><b>CONCLUSION</b>HLA-DR on Tregs is a good marker for viral replication and disease progression. The over-activation of Tregs might result in the decrease of Tregs.</p>

Clinical significance and detection of the expression of CD25- CD127- on CD4+ T cells in peripheral blood in patients with hepatitis B / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the clinical significance and detection of the expression of CD25- CD127- on CD4+ T cells in peripheral blood in patients with hepatitis B.</p><p><b>METHODS</b>The expression of CD25- CD127- on CD4+ T cells were measured by using flow cytometry in 53 patients with chronic hepatitis B, 53 carrier with hepatitis B virus and 26 healthy blood donors, and follow up 20 patients with HBV-DNA positive treated with interferon.</p><p><b>RESULTS</b>(1) Compared with healthy controls, the expression of CD25- CD127- on CD4+ T cells in patients and carrier with hepatitis B virus were lower (Q = 4.559, P < 0.05; Q = 6.230, P < 0.05). (2) The expression of CD25- CD127- on CD4+ T cells in patients with HBV-DNA positive (n = 77) was lower than that of negative (n = 29) (t = 2.290, P = 0.024). (3) Compared with the prior treatment,the expression of CD25- CD127- on CD4+ T cells in patients with B hepatitis were lower after interferon treated with 12 weeks (t = 2.469, P = 0.024).</p><p><b>CONCLUSION</b>It suggested that the CD25- CD127- expression on CD4+ T cells correlated with viral infections and cleared,exogenous interferon could decrease CD25- CD127- expression on CD4+ T cells.</p>

Levels of regulatory T cells in peripheral blood of children with idiopathic thrombocytopenic purpura / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the levels of CD4+CD25+CD127- and CD3+CD4-CD8- regulatory T (Treg) cells in peripheral blood of children with idiopathic thrombocytopenic purpura (ITP).</p><p><b>METHODS</b>The flow cytometry was used to detect the expression of CD4+CD25+CD127- and CD3+CD4-CD8- Treg cells in peripheral blood of 33 children with ITP and 21 healthy children.</p><p><b>RESULTS</b>The expression levels of CD4+CD25+CD127-［(2.7±1.7)% vs (4.8±1.6)%; P<0.01］and CD3+CD4-CD8-［(5.2±3.1)% vs (8.1±3.5)%; P<0.01］Treg cells in children with ITP were significantly lower than in the controls.</p><p><b>CONCLUSIONS</b>The expression levels of CD4+CD25+CD127- and CD3+CD4-CD8- Treg cells decrease in children with ITP, suggesting that CD4+CD25+CD127- and CD3+CD4-CD8- Treg cells might play a role in the pathogenesis of ITP.</p>

Detection and significance of CD4+ CD25int/high CD127low regulatory T cells in pediatric aplastic anemia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the expression of CD4+ CD25int/high CD127low regulatory T cells in peripheral blood (PB) and its relation to the quantity of Hb, WBC and platelet (Plt) in children with aplastic anemia (AA).</p><p><b>METHODS</b>Expression of CD4+ CD25int/high CD127low in PB was detected by flow cytometry in 22 children with AA before and after treatment and in 15 healthy controls. The relationships between CD4+CD25highCD127low and the quantity of Hb, WBC and Plt were evaluated.</p><p><b>RESULTS</b>Compared to controls, the percentages of CD4+ CD25+/CD4+, CD4+CD25high/CD4+, CD4+ CD25+ CD127low/CD4+ and CD4+CD25highCD127low/CD4+ in PB of AA patients decreased markedly at the active phase (P﹤0.05). By the recovery phase, the percentages of CD4+CD25+/CD4+, CD4+CD25high/CD4+, CD4+ CD25+ CD127low/CD4+ and CD4+CD25highCD127low/CD4+ increased significantly to the levels similar to the controls. There were significant positive relationships between the expression of CD4+CD25highCD127low cells and the quantity of Hb, WBC and Plt (r=0.499, 0.526, 0.540 respectively; P﹤0.05).</p><p><b>CONCLUSIONS</b>The decrease of the percentage of CD4+CD25int/highCD127low regulatory T cells might be associated with the development of pediatric AA. The CD4+CD25int/highCD127low regulatory T cells can serve as a marker for the evaluation of disease severity as well as a target of further study on immune treatment of AA.</p>

CD4+Foxp3+ regulatory T cells converted by rapamycin from peripheral CD4+CD25(-) naive T cells display more potent regulatory ability in vitro / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Rapamycin (RAPA) is a relatively new immunosuppressant drug that functions as a serine/threonine kinase inhibitor to prevent rejection in organ transplantation. RAPA blocks activation of T-effector (Teff) cells by inhibiting the response to interleukin-2. Recently, RAPA was also shown to selectively expand the T-regulator (Treg) cell population. To date, no studies have examined the mechanism by which RAPA converts Teff cells to Treg cells.</p><p><b>METHODS</b>Peripheral CD4(+)CD25(-) naive T cells were cultivated with RAPA and B cells as antigen-presenting cells (APCs) in vitro. CD4(+)CD25(-) T cells were harvested after 6 days and analyzed for expression of forkhead box protein 3 (Foxp3) using flow cytometry. CD4(+)CD25(+)CD127(-) subsets as the converted Tregs were isolated from the mixed lymphocyte reactions (MLR) with CD127 negative selection, followed by CD4 and CD25 positive selection using microbeads and magnetic separation column (MSC). Moreover, mRNA was extracted from converted Tregs and C57BL/6 naive CD4(+)CD25(+) T cells and Foxp3 levels were examined by quantitative real-time polymerase chain reaction (rt-PCR). A total of 1 x 10(5) carboxyfluorescein succinimidyl ester (CFSE)-labeled naive CD4(+)CD25(-) T cells/well from C57BL/6 mice were cocultured with DBA/2 or C3H maturation of dendritic cells (mDCs) (0.25 x 10(5)/well) in 96-well round-bottom plates for 6 days. Then 1 x 10(5) or 0.25 x 10(5) converted Treg cells were added to every well as regulatory cells. Cells were harvested after 6 days of culture and analyzed for proliferation of CFSE-labeled naive CD4(+)CD25(-) T cells using flow cytometry. Data were analyzed using CellQuest software.</p><p><b>RESULTS</b>We found that RAPA can convert peripheral CD4(+)CD25(-) naive T Cells to CD4(+)Foxp3(+) Treg cells using B cells as APCs, and this subtype of Treg can potently suppress Teff proliferation and maintain antigenic specificity.</p><p><b>CONCLUSION</b>Our findings provide evidence that RAPA induces Treg cell conversion from Teff cells and uncovers an additional mechanism for tolerance induction by RAPA.</p>

Studies about the level of CD4+ CD25+ regulatory T cells and relation between expression of Foxp3 and CD127 in peripheral blood of chronic HBV infection / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the level of CD4+ CD25+ Foxp3+ regulatory T cells and observe relation between expression of Foxp3 and CD127 in peripheral blood of chronic HBV infection.</p><p><b>METHODS</b>CD4+ CD25+ Foxp3+ and CD4+ CD25+ CD127low Treg in peripheral blood from 34 patients of immune tolerance stage, 26 patients of immune clearance stage and 31 patients of non-active status were quantitatively analyzed by flow cytometry.</p><p><b>RESULTS</b>Immune tolerance group presented a higher fraction of CD4+ CD25+ Foxp3+ and CD4+ CD25+ CD127low Treg than non-active group in chronic HBV infection (Z = -2.693, P = 0.007 and t = 3.251, P = 0.002), and HBV positive group also presented a higher fraction than non-active group (t = 2.266, P = 0.026 and t = 3.208, P = 0.002), But ALT normal group is similar to ALT abnormal group (P > 0.05). In this study, the relation between expression of CD127low and Foxp3+ from CD4+ CD25+ regulatory T cells was observed, and CD4+ CD25+ CD127low Treg presented a higher fraction than CD4+ CD25+ Foxp3+ Treg.</p><p><b>CONCLUSION</b>Peripheral Treg in HBV active replication group is higher than HBV negative group of chronic HBV infection. Expression of CD127low is consistent with Foxp3+ in CD4+ CD25+ regulatory T cells, but the former is significantly higher than the latter.</p>

Significance of CD4+ CD25+ CD127(low) regulatory T cells and notch1 pathway in the pathogenesis of aplastic anemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To quantify the CD4+ CD25+ CD127(low) regulatory T cell (Treg), the expression levels of forkhead/winged helix transcription factor FOXP3 and Notch1 mRNA in aplastic anemia (AA) patients before and after treatment, and explore the significance of Treg in pathogenesis of AA.</p><p><b>METHOD</b>CD4+ CD25+ and CD4+ CD25+ CD127(low) T cells in peripheral blood were examined with FACS in 29 AA patients at active phase, 14 at recovery phase, 11 at unrecovery phase, and 15 normal controls. The levels of FOXP3 mRNA and Notch1 mRNA expression were detected with RT-PCR, and the correlations between Treg, FOXP3 mRNA and Notchl mRNA were analyzed.</p><p><b>RESULTS</b>The percentages of peripheral activated CD4+ CD25+ T cells in AA patients at active phase (4.3 +/- 0.7)% and unrecovery phase (4.2 +/- 0.6)% were significantly higher than those in normal controls (2.4 +/- 0.8)% (P < 0.05). The proportion of these cells in AA patients at recovery phase was reduced to (2.6 +/- 0.7)% (P < 0.05), being no difference from that in control group. The number of CD4+ CD25+ CD127(low) T cells in AA patients at active phase (2.4 +/- 1.2)% and unrecovery phase (2.5 +/- 1.1)% was decreased significantly compared with those in normal controls (7.1 +/- 2.7)% (P < 0.01) and in AA patients at recovery phase (5.3 +/- 1.0)% (P < 0.01), there was no difference between the latter two groups. In active phase AA patients, the levels of FOXP3 mRNA and Notchl mRNA (0.260 +/- 0.011 and 0.018 +/- 0.005, respectively) were lower than that in control group (1.307 +/- 0.011 and 0.308 +/- 0.028, respectively) (P < 0.01 and P < 0.01). After treatment, the levels significantly increased to 1.287 +/- 0.012 and 0.281 +/- 0.013 (P < 0.01 and P < 0.01), but there was no difference with that of normal controls (P > 0.05). CD4+ CD25+ CD2(low) T cells and FOXP3 were positively related with Notchl (P < 0.01) in AA patients.</p><p><b>CONCLUSION</b>The decreased number and suppressive activity of CD4 CD25+ CD127(low) Treg cells in the peripheral blood of AA patients cause over-activation of autoreactive T cells and suppression of haematopoiesis. One of the mechanisms maybe the reduced expression of Notch1 in the target cells.</p>