Identification and structural analysis of dimeric chicken complement component 3d and its binding with chicken complement receptor 2.

Complement component 3d (C3d), the final cleavage product of complement component C3, interacts with CR2 and thus plays a crucial role in linking the innate and adaptive immune systems. Additionally, human C3d executes various functions in its dimeric form, which is more effective than its monomeric form. In this study, we aimed to explored whether chicken C3d (chC3d) exhibits similar characteristics, namely dimerization and binding of dimeric chC3d to chicken CR2 (chCR2). We investigated the interaction and co-localization of chC3d with itself using coimmunoprecipitation and confocal laser scanning microscopy, respectively. Then, dimeric chC3d was detected using native polyacrylamide gel electrophoresis and western blotting, and its equilibrium dissociation constant KD (827 nM) was determined using surface plasmon resonance. Finally, the interaction modes of dimeric chC3d were identified using molecular docking simulations, which revealed that dimeric chC3d could crosslink with chCR2 receptor. Overall, our findings will facilitate future explorations of the chicken complement system.

The correlation between Th17/Treg immune dysregulation and the disease severity in chronic spontaneous urticaria patients.

OBJECTIVE: Chronic spontaneous urticaria (CSU) has a profound impact on the sleep quality, productivity and overall quality of life of affected individuals. This study aimed to investigate the correlation between serum Th17/Treg immune dysregulation and the severity of CSU in patients. METHODS: Clinical baseline data of 120 CSU patients and matched healthy controls were recorded. The pruritus level, disease severity, and quality of life of CSU patients were assessed using the visual analogue scale, weekly Urticaria Activity Score and chronic urticaria quality of life questionnaire, respectively. The Th17/Treg cell ratio was detected by flow cytometry. ELISA was used to measure the levels of serum Th17 cytokines (IL-17, IL-21) and Treg cytokines (TGF-ß1, IL-35). Pearson's correlation analysis was conducted to examine the associations between these indicators. RESULTS: No significant differences were identified in terms of sex, age, and BMI between the two groups. However, CSU patients exhibited a significant increase in the Th17 cell ratio, as well as the elevated serum levels of TGF-ß1, IL-17 and, IL-21. Conversely, the proportion of Treg cells and the levels of IL-35 were remarkably decreased in CSU patients. Peripheral blood Th17 cells were negatively correlated with Treg cells. The severity of pruritus, life quality, and disease severity in CSU patients were positively correlated to Th17 cell ratio, and inversely correlated with Treg cell proportion. CONCLUSIONS: A positive correlation was found between the percentage of peripheral blood Th17 cell in CSU patients and the pruritus level, life quality, and disease severity. In constrast, there was a negative correlation between the proportion of peripheral blood Treg cells and these clinical parameters.

Quantitative analysis of the distribution and content of trace metal elements in liquid samples with a three-dimensional confocal x-ray technique.

Three-dimensional (3D) confocal x-ray fluorescence analysis technology is widely used, but the quantitative analysis of elemental spatial distributions of solid samples is complicated. This paper explores a quantitative analysis method that can be applied to solid samples. Fluorescence spectra of liquid samples are obtained on a 3D confocal x-ray fluorescence spectrometer. Curves are plotted showing the relationships between the fluorescence count intensity and the mass percentage of metal ions, and the respective fitting-curve equations are determined according to the curve morphology. Fluorescence intensity as a function of the mass percentage and depth position is derived from the samples for a particular acquisition time. These data play a potential role in the subsequent quantitative analysis of unknown mass percentages of solid samples.

Application of three-dimensional confocal x-ray fluorescence equipment in surface topography and depth contour scanning.

Three-dimensional microfocus x-ray fluorescence technology has been used to determine surface topography. The surface scanning technique initially facilitated surface topography reconstruction of the sample. This paper demonstrates the improved performance of its infrastructure, including a higher-precision translation platform, an ultrabright microfocus x-ray source and a rewritten scanning algorithm, leading to a new scanning technology that can depict the surface topography of samples with complex internal structures. The improved scanning technology can analyze the metal element information of layers at different depths. This paper presents studies of the surface and depth of coins and porcelain bottles from ancient times using this technique.