Induction of human regulatory innate lymphoid cells from group 2 innate lymphoid cells by retinoic acid

BACKGROUND: Group 2 innate lymphoid cells (ILC2s) play critical roles in induction and exacerbation of allergic airway inflammation. Thus, clarification of the mechanisms that underlie the regulation of ILC2 activation has received significant attention. Although ILCs are divided into three major subsets that mirror helper effector T-cell subsets, counterpart subsets of regulatory T (Treg) cells have not been well characterized. OBJECTIVE: We sought to determine the factors that induce regulatory ILCs (ILCregs). METHODS: IL-10+ ILCregs induced from ILC2s by retinoic acid (RA) were analyzed using RNA-sequencing and flow cytometry. ILCregs were evaluated in human nasal tissues from healthy individuals and patients with chronic rhinosinusitis with nasal polyp (CRSwNP), and in lung tissues from house dust mite (HDM)- or saline-treated mice. RESULTS: RA induced IL-10 secretion by human ILC2s, but not type-2 cytokines. IL-10+ ILCregs, converted from ILC2s by RA stimulation, expressed a Treg-like signature with the expression of IL-10, CTLA-4 and CD25, with down regulated effector type 2-related markers such as CRTH-2 and ST2, and suppressed activation of CD4+ T cells and ILC2s. ILCregs were rarely detected in human nasal tissue from healthy individuals or lung tissues from saline-treated mice, but were increased in nasal tissues from patients with CRSwNP and in lung tissues from HDM-treated mice. Enzymes for RA synthesis were up-regulated in airway epithelial cells during type-2 inflammation in vivo and by IL-13 in vitro. CONCLUSION: We have identified a unique immune regulatory and anti-inflammatory pathway by which RA converts ILC2s to ILCregs. Interactions between airway epithelial cells and ILC2s play an important roles in the generation of ILCregs

Paracrine IL-33 Stimulation Enhances Lipopolysaccharide-Mediated Macrophage Activation

BACKGROUND: IL-33, a member of the IL-1 family of cytokines, provokes Th2-type inflammation accompanied by accumulation of eosinophils through IL-33R, which consists of ST2 and IL-1RAcP. We previously demonstrated that macrophages produce IL-33 in response to LPS. Some immune responses were shown to differ between ST2-deficient mice and soluble ST2-Fc fusion protein-treated mice. Even in anti-ST2 antibody (Ab)-treated mice, the phenotypes differed between distinct Ab clones, because the characterization of such Abs (i.e., depletion, agonistic or blocking Abs) was unclear in some cases. METHODOLOGY/PRINCIPAL FINDINGS: To elucidate the precise role of IL-33, we newly generated neutralizing monoclonal Abs for IL-33. Exogenous IL-33 potentiated LPS-mediated cytokine production by macrophages. That LPS-mediated cytokine production by macrophages was suppressed by inhibition of endogenous IL-33 by the anti-IL-33 neutralizing mAbs. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that LPS-mediated macrophage activation is accelerated by macrophage-derived paracrine IL-33 stimulation

Challenge of 90Sr separation in environmental samples collected from the Fukushima exclusion zone

Fukushima Daiichi nuclear power plant (FDNPP) accident caused radioactive contamination with fission products (I, Te, Be, Cs, Sr isotopes, etc.). The fission products are neutron rich isotopes therefore beta particles will be released from the nucleus to reach stable isotope configuration. Since decay process is accomplished with gamma ray emission, gamma-ray spectroscopy is applied mainly for fission products determination in samples affected by nuclear accident. However, some fission products such as 90Sr, 89Sr are pure beta emitters. Since the energy distribution of the emitted electrons in the beta decay is continuous, element specific separation from the interfering beta emitters is essential for qualitative radioisotopes identification and subsequent measurement.The most important step for reliable 90Sr determination is the highly effective radionuclide separation. Even after five years of the Fukushima accident, there is radioactive contamination in environmental samples caused by radiocaesium isotopes (134Cs and 137Cs) around the Fukushima exclusion zone. The contamination of 90Sr is significantly lower, by four or five magnitudes than radiocaesium isotopes. Under this condition, the decontamination factor of caesium should be higher around six figures in order to eliminate interfering beta particles from radiocaesium isotopes during 90Sr analysis.In recent publication for chemical separation of 90Sr, extraction chromatography is preferred using Sr specific resin (crown ether). Therefore, caesium decontamination factor (DF) was determined in Sr resin using soil samples from the Fukushima exclusion zone with elevated 137Cs contamination (over 3,000 Bq g-1). The caesium separation was not adequate in every case (DF = 104 105), presence of radiocaesium affected the results of 90Sr measurement. Consequently, additional separation steps were required. Caesium purification, with classical selective oxalic acid precipitation method , was achieved with DF range from 50 to 100. However, applying oxalic precipitation combining with Eichrom Sr resin separation, interfering radiocaesium isotopes can be removed with high efficiency (DF>106). The details of this procedure will be discussed during the presentation.International Nuclear Chemistry Congress(INCC 2017

ASSESSMENT OF NATURAL RADIOACTIVITY OF THE BEACH PLACER SANDS IN MIDDLE COASTAL REGION OF TAMILNADU, INDIA

High Background Radiation Areas (HBRAs) have significant levels of radiations due to the presence of primordial radionuclides such as 232Th, 238U, and 40K in the beach placer sands. These sands are being extensively used for constructions of buildings. The aim of this study is to determine the radioactivity concentration of beach placer sands from 13 locations along the coastal line of Tamilnadu. The ambient dose rates measured in situ varied from 9 to 467 nGy h-1. The activity concentrations of radionuclide 228Ac, 226Ra and 40K were measured using High Purity Germanium (HPGe) gamma spectrometry. The mean activity concentrations of 228Ac, 226Ra, and 40K were 265 ± 1.7, 88 ± 7.1, 270 ± 3.7 Bq Kg-1, respectively. The annual effective dose rate ranges from 0.03 ± 0.002 to 0.7 ± 0.003 mSvy-1 and was higher than the UNSCEAR annual worldwide average value at a few places. X-ray fluorescence spectrometry (XRF) measurements were performed for the analyses of major elements as its oxide to know presence of minerals and origin of samples.ICHLERA 201

NATURAL RADIOACTIVITY MEASUREMENT AND DOSE ASSESSMENT OF BEACH PLACER SANDS IN THE COASTAL REGION OF TAMIL NADU (INDIA)

A preliminary study was carried out to determine the radioactivity concentration of 232Th, 226Ra and 40K in beach placer sands from 13 locations along the coast line of Tamil Nadu state, India. The ambient dose rates varied from 9 to 467 nGy h−1. The activity concentrations of radionuclide 232Th, 226Ra and 40K ranged from 5.2 to 683 Bq kg−1, 13 to 198 Bq kg−1 and 107 to 421 Bq kg−1, respectively. The annual effective dose rate ranges from 27 to 620 μSv y−1 and was higher at seven beaches in comparison to the UNSCEAR annual worldwide average value

Radiocesium and 40K distribution of river sediments and floodplain deposits in the Fukushima exclusion zone

In this study, radiocesium and 40K analysis were accomplished for samples of riverbed sediments and floodplain deposits collected from five rivers in the vicinity (< 20 km) of the damaged Fukushima Daiichi Nuclear Power Plant after seven years of the accident. Sediment particle size distribution and major oxide content were determined also for six selected samples to understand the retention and migration process of radiocesium in river environments. The radiocesium activity concentration varied from 103 ± 6 Bq·kg−1 to 22,000 ± 500 Bq·kg−1in riverbed sediments and from 92 ± 5 Bq·kg−1 to 117,000 ± 2000 Bq·kg−1 in floodplain deposits. The 134Cs/137Cs ratio (decay corrected to 15 March 2011) was 1.02 in the both samples. Compared to monitoring results in 2011, it was proved that the radiocesium distribution pattern had been changed remarkably during seven years. The radiocesium was primarily attached to fine clay particles but its sorption on sand and coarse sand particles was also considerable. The sorption process of radiocesium was not affected by the presence ofwater and moreover, after seven years of the Fukushima accident, a significant radiocesium migration cannot be expected without particle migration. Consequently, radiocesium will remain for a long time in the river environmentsand its redistribution is mainly affected by the erosion process of the sediments. The average 40K activity concentration of riverbed sediment and floodplain deposit samples was 640 ± 152 Bq·kg−1 changing from 319 ± 18 Bq·kg−1 to 916 ± 41 Bq·kg−1. In the river estuary zones, significant activity concentrationdecrements were observed for both radionuclides. This suggests that seawater intrusion has a decreasing effect on both natural and artificial radionuclides via wash-out of particulate radiocesium and 40K, and desorption of these radionuclides, but to reveal the detail of this process further investigations are required. The analysis of 40K can help in a simple and easy way to reveal the mineral composition differences of sediment samples