616 research outputs found
Early growth response gene 2 (Egr-2) controls the self-tolerance of T cells and prevents the development of lupuslike autoimmune disease
© 2008 Zhu et al. This article is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/).Maintaining tolerance of T cells to self-antigens is essential to avoid autoimmune disease. How self-reactive T cells are kept functionally inactive is, however, unknown. In this study, we show that early growth response gene 2 (Egr-2), a zinc-finger transcription factor, is expressed in CD44(high) T cells and controls their proliferation and activation. In the absence of Egr-2, CD44(high), but not CD44(low) T cells, are hyperreactive and hyperproliferative in vivo. The accumulation of activated CD4(+)CD44(high) T cells leads to the development of a late onset lupuslike autoimmune disease characterized by the accumulation of interferon (IFN)-gamma and interleukin (IL)-17-producing CD4(+) T cells, loss of tolerance to nuclear antigens, massive infiltration of T cells into multiple organs and glomerulonephritis. We found that the expression of cyclin-dependent kinase inhibitor p21cip1 was impaired in Egr-2-deficient T cells, whereas the expression of IFN-gamma and IL-17 in response to T cell receptor ligation was significantly increased, suggesting that Egr-2 activates the expression of genes involved in the negative regulation of T cell proliferation and inflammation. These results demonstrate that Egr-2 is an intrinsic regulator of effector T cells and controls the expansion of self-reactive T cells and development of autoimmune disease.The Biotechnology and Biological Sciences
Research Council, the Medical Research Council and the Wellcome Trust
ANO1 as a marker of oral squamous cell carcinoma and silencing ANO1 suppresses migration of human SCC-25 cells
Objectives: The purpose of this study is to confirm that ANO1 correlates with occurrence and metastasis of
OSCC.
Study Design: Immunohistochemistry was used to detect the expression of ANO1 in 160 specimens of OSCC
and normal tissues. Lentiviral silencing ANO1 was used in scc-25 cell line to study the cell migration and cell
detachment.
Results: Immunohistochemical staining revealed that ANO1 was expressed in a large majority (132 out of 160,
82.5%) of OSCC specimens and that the rate of ANO1 expression in OSCC was significantly higher than that of
normal tissue (
P
<0.05); The rate of ANO1 expression was higher in metastatic tumors than in non-metastatic
tumors, and the difference was significant (
P
<0.05). The results of cell migration assay showed that the percent
-
age of cells through the membrane was 26.61 ±0.81 in assay group, and 54.26 ±3.74 in control group, respectively
(t =-16.22,
P
<0.0001). The results of cell detachment assay showed that the percentage of cells detachment was
37.42 ±0.90 in assay group, and 87.38 ±1.59 in control group, respectively (t=-62.34,
P
<0.0001). The results of
wound healing assay showed the assay group had a reduced migration rate compared with the control group in 32
h (F=1038.78,
P
<0.0001). Wound closure was no significantly different between the assay and control cells when
DIDS was used in wound healing assay (F=4.61,
P
>0.05).
Conclusions: Our study shows that abnormal expression of ANO1 correlated with the occurrence and metastasis
of OSCC in clinical specimens and that silencing ANO1 greatly reduced migration ability of scc-25 cells. Calcium
activated chloride channel activity of ANO1 promoted the cell migration. Thus, ANO1 could represent a new
diagnostic biomarker and a potentially important therapeutic target of OSCC
Role of a bacterial polar adhesion factor during legume-microbe symbiosis
Sinorhizobium meliloti (S. meliloti) establishes symbiosis with legume hosts through the formation of nitrogen-fixation root nodules
Research and application of time series algorithms in centralized purchasing data
Based on the online transaction data of COSCO group's centralized procurement platform, this paper studies the clustering method of time series type data. The different methods of similarity calculation, different clustering methods with different K values are analysed, and the best clustering method suitable for centralized purchasing data is determined. The company list under the corresponding cluster is obtained. The time series motif discovery algorithm is used to model the centroid of each cluster. Through ARIMA method, we also made 12 periods of prediction for the centroid of each category. This paper constructs a matrix of "Customer Lifecycle Theory - Five Elements of Marketing ", and puts forward corresponding marketing suggestions for customers at different life cycle stages
Early growth response genes 2 and 3 regulate the expression of Bcl6 and differentiation of T follicular helper cells
T follicular helper (Tfh) cells support differentiation of B cells to plasma cells and high affinity antibody production in germinal centers (GC) and Tfh differentiation requires the function of B cell lymphoma 6 (Bcl6). We have now discovered that early growth response gene (Egr) 2 and 3 directly regulate the expression of Bcl6 in Tfh cells which is required for their function in regulation of GC formation. In the absence of Egr2 and 3, the expression of Bcl6 in Tfh cells is defective leading to impaired differentiation of Tfh cells resulting in a failure to form GCs following virus infection and defects in production of anti-viral antibodies. Enforced expression of Bcl6 in Egr2/3 deficient CD4 T cells partially restored Tfh differentiation and GC formation in response to virus infection. Our findings demonstrate a novel function of Egr2/3 which is important for Tfh cell development and Tfh cell mediated B cell immune responses.This work was supported by Arthritis Research UK. The authors declare that they have no conflicts of interest with the contents of this article
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