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

Early growth response gene-2 (Egr-2) regulates the development of B and T cells

The study was supported by Arthritis Research UK. Copyright @ 2011 Li et al.BACKGROUND: Understanding of how transcription factors are involved in lymphocyte development still remains a challenge. It has been shown that Egr-2 deficiency results in impaired NKT cell development and defective positive selection of T cells. Here we investigated the development of T, B and NKT cells in Egr-2 transgenic mice and the roles in the regulation of distinct stages of B and T cell development. METHODS AND FINDINGS: The expression of Egr1, 2 and 3 were analysed at different stages of T and B cell development by RT-PCT and results showed that the expression was strictly regulated at different stages. Forced expression of Egr-2 in CD2+ lymphocytes resulted in a severe reduction of CD4+CD8+ (DP) cells in thymus and pro-B cells in bone marrow, which was associated with reduced expression of Notch1 in ISP thymocytes and Pax5 in pro-B cells, suggesting that retraction of Egr-2 at the ISP and pro-B cell stages is important for the activation of lineage differentiation programs. In contrast to reduction of DP and pro-B cells, Egr-2 enhanced the maturation of DP cells into single positive (SP) T and NKT cells in thymus, and immature B cells into mature B cells in bone marrow. CONCLUSIONS: Our results demonstrate that Egr-2 expressed in restricted stages of lymphocyte development plays a dynamic, but similar role for the development of T, NKT and B cells.This article is provided by the Brunel Open Access publishing fund

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

Egr2 and 3 control adaptive immune responses by temporally uncoupling expansion from T cell differentiation

Egr2 and 3 are important for maintaining immune homeostasis. Here we define a fundamental function of Egr2 and 3 operating as a checkpoint that controls the transition between clonal expansion and differentiation of effector T cells. Egr2 and 3 deficiency resulted in defective clonal expansion, but hyper-activation and excessive differentiation of T cells in response to viral infection. Conversely, sustained Egr2 expression enhanced expansion, but severely impaired effector differentiation. Egr2 bound to and controlled the expression of genes regulating proliferation (Myc, Myb) and differentiation repressors (Bcl6, Id3), while repressing transcription factors required for effector function (Zeb2, RORa, RORc, Bhlhe40). Egr2 and 3 expression in T cells was regulated reciprocally by antigen and IFNγ providing a mechanism for adjusting proliferation and differentiation of individual T cells. Thus, Egr2 and 3 are upstream regulators of effector CD4 and CD8 T cells that are essential for optimal responses with limited immunopathology

Protective effects of combined Mycobacterium bovis BCG and interleukin-12 vaccination on airway inflammation in a murine model of allergic asthma

Purpose. Allergic asthma is characterized by chronic airway inflammation and airway hyperresponsiveness driven by allergen-specific T helper (Th)2 cells. Mycobacterium bovis bacillus Calmette-Guérin (BCG) vaccination has been documented to suppress Th2 responses and allergic airway inflammation in animal models. Since interleukin (IL)-12 is capable of inhibiting Th2 responses, we sought to investigate whether IL-12 could function as an adjuvant to increase the efficacy of BCG vaccination against allergic asthma. Methods. BALB/c neonatal mice (24 mice, 48-72 h old) were randomly divided into 3 subgroups (n = 8 for each group) to be immunized with PBS (control) or BCG with or without DNA plasmid-expressing IL-12. All of the mice were then sensitized and provoked with ovalbumin (OVA) to establish a model of allergic asthma. Results. Mice vaccinated with BCG alone showed a significant reduction in airway inflammation, percentage of eosinophils in bronchoalveolar lavage (BAL) fluid, and serum OVA-specific immunoglobulin E (IgE) levels in comparison with control animals. The suppressive effects of BCG were substantially augmented by the combination with IL-12. Furthermore, a decreased IL-4 and increased interferon-gamma (IFN-γ) production in BAL fluid were observed in animals inoculated with BCG alone or with IL-12 relative to control animals. Conclusion. Our data indicate that the combined vaccination with BCG and IL-12 yields a favorable outcome in prevention of experimental allergic airway inflammation, which is likely mediated through triggering a shift from a Th2 response to a Th1 response

Challenges of massive access in highly dense LTE-advanced networks with machine-to-machine communications

The Main purpose of the present study was to evaluate whether REM sleep deprivation (RSD) influences the development of anhedonia in rats in a peripheral neuropathy model induced by sciatic nerve constriction injury (CCI). Anhedonia was measured by assessing daily water/sucrose intake. Four groups were assessed: control (CTRL), CCI, RSD, and CCI + RSD (n = 8/group). Intake data were collected at baseline (mean of 3 days), on the 1st and 2nd days after a CCI or SHAM procedure, during 4 days of RSD, and during an additional 10 days (rebound period or equivalent in home-cage rats). Control rats spontaneously and progressively increased Sucrose intake, reaching final daily volumes significantly greater than respective initial baseline amounts. RSD promoted an additional and immediate significant increase in sucrose intake during sleep deprivation days. The CCI group did not display a spontaneous, progressive increase in sucrose intake. When CO was combined with RSD, the increase in sucrose intake induced by RSD was significantly lower than in animals submitted to RSD alone; the (CCI + RSD) group also failed to show a spontaneous and progressive increase in sucrose intake. The present findings indicate that animal model of chronic neuropathy exhibits reduced sucrose ingestion. Accordingly, this anhedonic condition that constitutes to the core manifestation of depressive states did not occur in response to a single episode of total RSD. (C) 2009 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Identification and characterization of two novel antioxidant peptides from silkworm pupae protein hydrolysates

Silkworm pupae are a kind of insect resource food that rich of good quality protein. To identify the peptide with high antioxidant activity from silkworm pupae protein hydrolysates, and provide the basis for the application of silkworm pupae protein hydrolysates and antioxidant peptides in functional foods, silkworm pupae proteins were hydrolysed by a dual-enzyme system consisting of acidic protease and neutral protease. The hydrolysates were purified sequentially by ultrafiltration, gel filtration chromatography and high-performance liquid chromatography (HPLC). The ABTS radical scavenging activity was used to evaluate antioxidant activity. Fractions with high activity were further analyzed by liquid chromatography- tandem mass spectrometry (LC–MS/MS). Two peptides, FKGPACA and SVLGTGC with molecular weights of 692.34 and 635.30 Da were obtained. To further determine the major active sites of FKGPACA and SVLGTGC, four peptides, FKGP, ACA, SVLG and TGC were artificially synthesized. ACA and TGC had higher ABTS radical scavenging activities than FKGP and SVLG. The main active sites of FKGPACA and SVLGTGC were possibly located in the ACA and TGC fragments, which are related to Cys, Ala or Thr residues. Both FKGPACA and SVLGTGC proved to good antioxidants even after high-temperature thermal processing for 1 h. After digestion with pepsin, the ABTS radical scavenging activity of FKGPACA was stable, while the ABTS radical scavenging activity of SVLGTGC decreased slightly. After further digestion with pancreatin, the ABTS radical scavenging activities of FKGPACA and SVLGTGC decreased by 10.59% and 43.56%, respectively. After digestion with chymotrypsin, the ABTS radical scavenging activities of FKGPACA and SVLGTGC were stable. The silkworm pupae protein hydrolysates and FKGPACA could be potentially used as natural antioxidants in functional foods

Quantitative Analysis of Anthocyanins in Grapes by UPLC-Q-TOF MS Combined with QAMS

A method for quantifying the anthocyanins in grapes was firstly developed by ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOFMS) combined with quantitative analysis of multi-components by single marker (QAMS). A total of 10 main anthocyanins were analyzed by using peonidin 3-O-glucoside as the reference standard. The accuracy of this method was evaluated by an established and validated external standard quantification method with 10 reference compounds. The standard method difference (SMDs) of the quantification results between QAMS and the external standard methodwasless than 15%. Furthermore, the QAMS method was used to analyzefour batches of grapes and the data was compared with those obtained using the external standard method. No significant difference wasobtained in the results obtained by both methods. These results indicated that the QAMS method could accurately determine the anthocyanins in grapes. This method can provide a basis to address the absence of reference standards for analyzing anthocyanins in other foods