Interferon Regulatory Factors 1 and 2 Play Different Roles in MHC II Expression Mediated by CIITA in Grass Carp, Ctenopharyngodon idella

Expression of major histocompatibility complex class II (MHC II) molecules, which determines both the immune repertoire during development and subsequent triggering of immune responses, is always under the control of a unique (MHC class II) transactivator, CIITA. The IFN-γ-inducible MHC II expression has been extensively and thoroughly studied in humans, but not in bony fish. In this study, the characterization of CIITA was identified and its functional domains were analyzed in grass carp. The absence of GAS and E-box in the promoter region of grass carp CIITA, might imply that the cooperative interaction between STAT1 and USF1 to active the CIITA expression, found in mammals, is not present in bony fish. After the transfection of IFN-γ or IFN-γ rel, only IFN-γ could induce MHC II expression mediated by CIITA. Moreover, interferon regulatory factor (IRF) 2, which cooperates with IRF1 to active the CIITA promoter IV expression in mammals, played an antagonistic role to IRF1 in the activation of grass carp CIITA. These data suggested that grass carp, compared with mammals, has both conservative and unique mechanisms in the regulation of MHC II expression.

Enantioselective Resolution Copolymerization of Racemic Epoxides and Anhydrides: Efficient Approach for Stereoregular Polyesters and Chiral Epoxides

Herein we report an efficient strategy for preparing isotactic polyesters and chiral epoxides via enantioselective resolution copolymerization of racemic terminal epoxides with anhydrides, mediated by enantiopure bimetallic complexes in conjunction with a nucleophilic cocatalyst. The chirality of both the axial linker and the diamine backbones of the ligand are responsible for the chiral induction of this kinetic resolution copolymerization process. The catalyst systems exhibit exceptional levels of enantioselectivity with a kinetic resolution coefficient exceeding 300 for various racemic epoxides, affording highly isotactic copolymers (selectivity factors of more than 300) with a completely alternating structure and low polydispersity index. Most of the produced isotactic polyesters are typical semicrystalline materials with melting temperatures in the range from 77 to 160 °C.

Investigating the potential immune role of IL-35 in grass carp (Ctenopharyngodon idella)

Interleukin-35 (IL-35) is a member of the IL-12 cytokine family and a heterodimeric protein formed by Epstein-Barr virus-induced gene 3 (EBI3) and IL-12p35. Emerging evidence showed that IL-35 is a key player in the regulation of cellular communication, differentiation, and inflammation. To date, no studies on fish IL-35 have been documented. In this work, we first identify two splicing isoforms of EBI3, EBI3a and EBI3b, from grass carp (Ctenopharyngodon idella). EBI3a is composed of 299 amino acid residues and possesses an immunoglobulin-like (Ig-like) domain and a fibronectin type 3 (FN3) domain that is a conservative domain in vertebrate EBI3. However, the EBI3b is composed of 177 amino acid residues and only contains an Ig-like domain. The result of Co-immunoprecipitation suggests that only EBI3a can associate with IL-12p35 to form IL-35 in grass carp. Like the function of IL-35 in human and mouse, recombinant grass carp IL-35 protein could induce the expression of genes EBI3a, IL-12p35, and CD25-like and downregulate the expression of genes CD4-1, CD4-2, IL-17A/F1, and RORγ2. Taken together, these results indicate for the first time that a teleost IL-35 may also have the ability to induce regulatory T (Treg) cells, inhibit effector T (Teff) cell proliferation and restrict the differentiation and function of T helper 17 (Th17) cells in teleost.

Organocatalytic cycloaddition of carbonyl sulfide with propargylic alcohols to 1,3-oxathiolan-2-ones

Lewis base-COS adducts were firstly studied as organocatalysts for the cyclization of propargylic alcohols with carbonyl sulfide.

Characterization of grass carp CD40 and CD154 genes and the association between their polymorphisms and resistance to grass carp reovirus

In bony fish, CD40 and CD154 are two very important costimulatory molecules involved in T and B cell cooperation in thymus-dependent antibody production. In the current study, we identified the cDNAs of CD40 and CD154 and analyzed their genomic structures in grass carp. Quantitative real-time PCR indicated that the CD40 and CD154 were mainly expressed in immune organs. After challenge with grass carp reovirus (GCRV), these two genes were up-regulated at 72 h in head kidney and spleen. Moreover, seven and five single nucleotide polymorphisms (SNPs) were identified in the CD40 and CD154 respectively. Statistical analysis indicated that three SNPs in the coding region of the CD40 were significantly associated with the resistance of grass carp against GCRV. These results indicated that CD40 and CD154 play important roles in the responses to GCRV in grass carp. The SNP markers in the CD40 associated with the resistance to GCRV may facilitate the disease-resistant breeding of grass carp.

Tandem Lewis Pair Polymerization and Organocatalytic Ring-Opening Polymerization for Synthesizing Block and Brush Copolymers

Lewis pair polymerization is a powerful method for preparing soluble polymers bearing pendant active vinyl groups by directly polymerizing dissymmetric divinyl polar monomers. Herein, we present a strategy for synthesizing block and brush copolymers via tandem Lewis pair polymerization of methacrylates, "thiol-ene" click reaction and organocatalytic ring-opening polymerization of lactide.

Highly efficient conversion of CO2 to cyclic carbonates with a binary catalyst system in a microreactor: intensification of “electrophile–nucleophile” synergistic effect

An intensification of the “electrophile–nucleophile” synergistic effect was achieved in a microreactor for the coupling reaction of CO₂ and epoxides mediated by the binary Al complex/ternary ammonium salt catalyst system. The microreactor technology is proven to be a powerful tool for the preparation of cyclic carbonates with an improved reaction rate and a wide substrate scope.

An intensification of the “electrophile–nucleophile” synergistic effect was achieved in a microreactor for the coupling reaction of CO₂ and epoxides mediated by the binary Al complex/ternary ammonium salt catalyst system.

Magnetic impurity doping induced spin-glass state and short-range zigzag order in the honeycomb iridate Na2IrO3

Based on the modified Heisenberg-Kitaev model, the effects of magnetic substitution on the magnetic properties of the honeycomb-lattice iridate [Formula: see text] [Formula: see text] are studied using Monte Carlo simulations. It is observed that the long-range zigzag state of the original system is rather fragile and can be replaced by a spin-glass state even for small substitution, well consistent with the experimental observation in Ru-substituted samples (Mehlawat et al 2015 Phys. Rev. B 92 134412). Both the disordered Heisenberg and Kitaev interactions caused by the magnetic ion-doping are suggested to be responsible for the magnetic phase transitions in the system. More interestingly, a short-range zigzag order is suggested to survive above the freezing temperature even at high magnetic impurity doping levels.