Splenic CD8(+) T cells secrete TGF-beta 1 to exert suppression in mice with anterior chamber-associated immune deviation

Background CD8(+) regulatory T cells (Treg) have been considered to be involved in a model of ocular-induced tolerance, known as anterior chamber-associated immune deviation (ACAID). The mechanisms of suppression by CD8(+) T cells in ACAID remain only poorly understood. TGF-beta 1 is considered as an inhibitory cytokine for immunosuppression in some models. The production of TGF-beta 1 by CD8(+) T cells in ACAID, and whether CD8+ T cells exert suppression through TGF-beta 1, is unknown. Methods The suppressive effect of CD8(+) T cells in ACAID mice was determined by a local adoptive transfer (LAT) assay. The production of TGF-beta 1 by CD8(+) T cells was measured by enzyme-linked immunosorbent assay (ELISA). Anti-TGF-beta 1 antibodies were used in the LAT assay to test if they could block the inhibitory effect of CD8(+) T cells. Results CD8(+) T cells from ACAID mice were shown to block the delayed-type hypersensitivity (DTH) response in an antigen-specific manner in a LAT assay. These CD8+ T cells secreted TGF-beta 1, and their suppression could partially be blocked by anti-TGF-beta 1 antibodies. Conclusions Our study confirms that CD8+ T cells from ACAID mice possess inhibitory properties. This population exerts part of its suppressive function via the production of TGF-beta 1

Quantifying atmospheric nitrogen deposition through a nationwide monitoring network across China

A Nationwide Nitrogen Deposition Monitoring Network (NNDMN) containing 43 monitoring sites was established in China to measure gaseous NH3, NO2, and HNO3 and particulate NH4+ and NO3− in air and/or precipitation from 2010 to 2014. Wet/bulk deposition fluxes of Nr species were collected by precipitation gauge method and measured by continuous-flow analyzer; dry deposition fluxes were estimated using airborne concentration measurements and inferential models. Our observations reveal large spatial variations of atmospheric Nr concentrations and dry and wet/bulk Nr deposition. On a national basis, the annual average concentrations (1.3–47.0 μg N m−3) and dry plus wet/bulk deposition fluxes (2.9–83.3 kg N ha−1 yr−1) of inorganic Nr species are ranked by land use as urban > rural > background sites and by regions as north China > southeast China > southwest China > northeast China > northwest China > Tibetan Plateau, reflecting the impact of anthropogenic Nr emission. Average dry and wet/bulk N deposition fluxes were 20.6 ± 11.2 (mean ± standard deviation) and 19.3 ± 9.2 kg N ha−1 yr−1 across China, with reduced N deposition dominating both dry and wet/bulk deposition. Our results suggest atmospheric dry N deposition is equally important to wet/bulk N deposition at the national scale. Therefore, both deposition forms should be included when considering the impacts of N deposition on environment and ecosystem health

A strategy to improve cyclic performance of LiNi05Mn 15O4 in a wide voltage region by Ti-doping

A strategy to improve cyclic performance of 5 V spinel LiNi 0.5Mn1.5O4 in a wide voltage region (4.95-2.0 V) by Ti-doping has been proposed and demonstrated for the first time. The effects of Ti substitution for Mn on the structure and electrochemical properties of the LiNi0.5Mn1.5-xTixO 4 (0 &le x &le 0.6) during cycling between 4.95 and 2.0 V were investigated. X-ray diffraction (XRD) results show that all of these materials are cubic spinel structure with a space group of Fd3ˉm, where their unit cell parameter a increases with the substituting amount of Mn by Ti, which is in agreement with the fact that the ionic radius of Ti4+ (74.5 pm) is much larger than that of Mn4+ (67 pm). Electrochemical test results show that proper amount of Ti substitution for Mn is able to significantly improve the cyclic performance of LiNi0.5Mn1.5-xTi xO4 spinel during cycling at 4.95-2.0 V, especially for the capacity retention of the ca. 2.7 V plateau. Take LiNi0.5Mn 1.0Ti0.5O4 as an example, the capacity retention in the upper (4.95-3.0 V) and lower voltage (3.0-2.5V) regions after 100 cycles are 57.1% and 79.8%, respectively, while they are only 47.0% and 24.5% for un-substituted LiNi0.5Mn1.5O4 sample, respectively. ? 2013 The Electrochemical Society

Longitudinal study of anterior segment inflammation by ultrasound biomicroscopy in patients with acute anterior uveitis

This study aimed to investigate dynamic changes in the anterior segment in patients with acute anterior uveitis (AAU) using ultrasound biomicroscopy (UBM). Acute anterior uveitis was diagnosed in 18 patients according to history and ocular examinations. Ultrasound biomicroscopy was performed and the results at three time-points (within 2 weeks of the uveitis attack, and at 2-4 weeks and 6 weeks after it) were analysed. The relationships between clinical manifestations and UBM findings were also evaluated. All investigated AAU patients showed severe ciliary injection, numerous dust keratic precipitates (KPs), aqueous flare and inflammatory cells, and were treated predominantly with corticosteroid and cycloplegic eyedrops. Ultrasound biomicroscopy showed a large number of cells in the anterior and posterior chamber, marked oedema and exudates in and around the iris and ciliary body within 2 weeks of AAU onset. These abnormalities were dramatically improved at 2-4 weeks and almost resolved at 6 weeks and thereafter. Ultrasound biomicroscopy reveals severe inflammatory changes in and around the ciliary body in patients with AAU. These signs rapidly resolve upon treatment

CD4(+)CD25(+)Tregs express an increased LAG-3 and CTLA-4 in anterior chamber-associated immune deviation

Background Regulatory CD4+CD25+ T cells have been proven to be essential for maintenance of peripheral tolerance and autoimmune diseases. ACAID is a model of immune privilege in the eye. Relatively little is known about the role and phenotype of these regulatory CD4+CD25+ T cells in ACAID. Methods Injection of OVA into the anterior chamber of BALB/C mice was performed to induce ACAID. The frequencies of splenic CD4+CD25+ Tregs and the expression of CTLA-4 and LAG-3 on these cells were determined by flow cytometry. Magnetic cell sorting was used to isolate CD4+CD25+ and CD4+CD25¿T cells. The function of CD4+CD25+ T cells was detected by in vitro immunosuppression assays and in vivo adoptive transfer. Results ACAID was successfully induced following an i.c. injection of OVA. Frequencies of CD4+CD25+ and Tregs were significantly increased in ACAID mice as compared to those in controls. The CD4+CD25+ T cells stimulated with OVA in ACAID mice showed a stronger suppressive ability in vitro than those seen in non-ACAID mice. CD4+CD25+ T cells from ACAID mice, but not from non-ACAID mice, were able to suppress DTH responses in an antigen-specific manner following adoptive transfer. The frequencies of CTLA-4 or LAG-3 on Tregs in ACAID mice were higher as compared with those in naive mice. Conclusion Splenic CD4+CD25+Foxp3+T cells expressing CTLA4 and LAG3 play an important role in the induction of ACAI

Greenhouse gas emissions from a wheat-maize double cropping system with different nitrogen fertilization regimes

Here, we report on a two-years field experiment aimed at the quantification of the emissions of nitrous oxide (N2O) and methane (CH4) from the dominant wheat maize double cropping system in North China Plain. The experiment had 6 different fertilization strategies, including a control treatment, recommended fertilization, with and without straw and manure applications, and nitrification inhibitor and slow release urea. Application of N fertilizer slightly decreased CH4 uptake by soil. Direct N2O emissions derived from recommended urea application was 0.39% of the annual urea-N input. Both straw and manure had relatively low N2O emissions factors. Slow release urea had a relatively high emission factor. Addition of nitrification inhibitor reduced N2O emission by 55%. We conclude that use of nitrification inhibitors is a promising strategy for N2O mitigation for the intensive wheat maize double cropping systems. (C) 2013 Elsevier Ltd. All rights reserved