NKG2D ligand RAE1ε induces generation and enhances the inhibitor function of myeloid‐derived suppressor cells in mice

Expression of surface NKG2D ligands on tumour cells, which activates nature killer (NK) cells and CD8⁺ T cells, is crucial in antitumour immunity. Some types of tumours have evolved mechanisms to suppress NKG2D‐mediated immune cell activation, such as tumour‐derived soluble NKG2D ligands or sustained NKG2D ligands produced by tumours down‐regulate the expression of NKG2D on NK cells and CD8⁺ T cells. Here, we report that surface NKG2D ligand RAE1ε on tumour cells induces CD11b⁺Gr‐1⁺ myeloid‐derived suppressor cell (MDSC) via NKG2D in vitro and in vivo. MDSCs induced by RAE1ε display a robust induction of IL‐10 and arginase, and these MDSCs show greater suppressive activity by inhibiting antigen‐non‐specific CD8⁺ T‐cell proliferation. Consistently, upon adoptive transfer, MDSCs induced by RAE1ε significantly promote CT26 tumour growth in IL‐10‐ and arginase‐dependent manners. RAE1ε moves cytokine balance towards Th2 but not Th1 in vivo. Furthermore, RAE1ε enhances inhibitory function of CT26‐derived MDSCs and promotes IL‐4 rather than IFN‐γ production from CT26‐derived MDSCs through NKG2D in vitro. Our study has demonstrated a novel mechanism for NKG2D ligand⁺ tumour cells escaping from immunosurveillance by facilitating the proliferation and the inhibitory function of MDSCs.     

Temperature Sensor Based on Hollow Fiber Filled with Graphene-Ag Composite Nanowire and Liquid

A temperature sensor based on hollow fiber (HF) filled with graphene-Ag composite nanowire and liquid is presented. The coupling properties and sensing performance are numerically analyzed by finite element method using wavelength and amplitude interrogations. Results show that the sensor exhibiting strong birefringence with x-polarized peak provides much higher sensitivities and better signal-to-noise ratio (SNR) than y-polarized, which is more suitable for temperature detection. The graphene-Ag composite nanowire can not only solve the oxidation problem but also avoid the metal coating. Moreover, it provides better performance than other similar works like Au-Ag nanowire-filled, Au nanowire-filled, and Ag nanowire-filled sensors. Contrary to the blue shift of traditional SPR temperature sensors, the resonance peak shifts to the longer wavelength in our device when temperature increases and the high sensitivity 9.44 nm/ °C is obtained. The influences of nanowire diameter, grapheme-layer thickness on the designed sensor, are also investigated. This work can provide a reference for developing a high sensitivity, real-time, remote sensing, and distributed temperature SPR sensor.     

Multi-Band Ultra-Sharp Transmission Response in All-Dielectric Resonant Structures Containing Kerr Nonlinear Media

All-dielectric resonant structure (ADRS) consisting of high-index nonlinear dielectrics has been theoretically and numerically demonstrated with multi-band ultra-sharp transmission response in this work. Bandwidth down to sub-nanometer and spectral Q-factor up to 920 are achieved in this ADRS-based metamaterial-like platform. Strong resonant electric field distributions by the high-index dielectric resonators and efficient coupling between the layered dielectric particles and the cavity mainly contribute to the multiple narrowband light transmission filtering. By using a Kerr nonlinear medium as the resonant dielectric, the positions of the transmission dips in the spectrum can be actively tuned by the incident light intensity. Due to the ultra-narrow spectral feature and the strong electric field distribution by the resonators, an efficient all-optical switching behavior with high spectral difference intensity and contrast ratio is obtained. Further study presents the observed multi-band transmission with high scalability by tuning the structural parameters. These optical features hold the predicted ADRS be potentially applied to constructing dielectric metamaterial-based all-optical switching or active subtractive transmission filtering with low power threshold at sub-diffraction scale.     

Analysis of conformational motions and related key residue interactions responsible for a specific function of proteins with elastic network model

Protein collective motions play a critical role in many biochemical processes. How to predict the functional motions and the related key residue interactions in proteins is important for our understanding in the mechanism of the biochemical processes. Normal mode analysis (NMA) of the elastic network model (ENM) is one of the effective approaches to investigate the structure-encoded motions in proteins. However, the motion modes revealed by the conventional NMA approach do not necessarily correspond to a specific function of protein. In the present work, a new analysis method was proposed to identify the motion modes responsible for a specific function of proteins and then predict the key residue interactions involved in the functional motions by using a perturbation approach. In our method, an internal coordinate that accounts for the specific function was introduced, and the Cartesian coordinate space was transformed into the internal/Cartesian space by using linear approximation, where the introduced internal coordinate serves as one of the axes of the coordinate space. NMA of ENM in this internal/Cartesian space was performed and the function-relevant motion modes were identified according to their contributions to the specific function of proteins. Then the key residue interactions important for the functional motions of the protein were predicted as the interactions whose perturbation largely influences the fluctuation along the internal coordinate. Using our proposed methods, the maltose transporter (MalFGK₂) from E. Coli was studied. The functional motions and the key residue interactions that are related to the channel-gating function of this protein were successfully identified.