Multidynamic Poly(oxime–carbamate) Elastomers with Rosin Moieties

General thermoset materials are prone to hidden cracks and aging during use and have strong cross-linked network structures, resulting in a waste of resources due to the difficulty of recycling after use. The introduction of reversible covalent/noncovalent bonds into materials can impart self-healing and recyclable properties, thereby extending the life cycle of the materials, which is in line with the goal of sustainable development. In this study, we prepared a series of multidynamic poly­(oxime–carbamate) elastomers derived from rosin, based on a synergistic reinforcement strategy of hydrogen, metal–ligand coordination, and oxime–carbamate bonds using acrylic rosin and glycidyl methacrylate ester as monomers. Furthermore, the thermal, mechanical, dynamic, self-healing, and recyclability properties of the elastomers were investigated. The results showed that the prepared poly­(oxime–carbamate) elastomers had good thermal stability (Td5% > 235 °C), solvent resistance and self-healing properties (120 min of healing at 70 °C with 89.5 ± 1.8% self-healing efficiency), excellent tensile strength (19.3 ± 0.5 MPa), toughness (44.3 ± 1.5 MJ m–3), and good recyclability. Furthermore, strain sensors constructed by using these elastomers have high stability. This study provides a research basis for the development of high-performance biobased self-healing materials for wearable electronics and flexible electronics applications

IL-17A Promotes Pulmonary B-1a Cell Differentiation <i>via</i> Induction of Blimp-1 Expression during Influenza Virus Infection

<div><p>B-1 cells play a critical role in early protection during influenza infections by producing natural IgM antibodies. However, the underlying mechanisms involved in regulating this process are largely unknown. Here we found that during influenza infection pleural cavity B-1a cells rapidly infiltrated lungs, where they underwent plasmacytic differentiation with enhanced IgM production. This process was promoted by IL-17A signaling <i>via</i> induction of Blimp-1 expression and NF-κB activation in B-1a cells. Deficiency of IL-17A led to severely impaired B-1a-derived antibody production in the respiratory tract, resulting in a deficiency in viral clearance. Transfer of B-1a-derived natural antibodies rescued <i>Il17a</i>^-/- mice from otherwise lethal infections. Together, we identify a critical function of IL-17A in promoting the plasmacytic differentiation of B-1a cells. Our findings provide new insights into the mechanisms underlying the regulation of pulmonary B-1a cell response against influenza infection.</p></div

B-1a cell-derived natural antibodies are required for early protection of <i>Il17a</i>^-/- mice from death.

<p>(A) Representative flow cytometric profiles (n = 5) show CD19⁺IgM⁺CD43⁺CD5⁺ B-1a cells in lung tissue of H1N1-infected WT mice from 0 to 7 dpi. Frequencies of B-1a cells are indicated. (B) Absolute numbers of B-1a cells represented in (A) are shown. Data are mean values ± SEM. ***, p < 0.001 for each group compared to 0 dpi group (n = 5). (C) Examination of the lung tissues of WT mice at 2 dpi by immunofluorescence microscopy. Sections were stained for CD19 (cyan), CD43 (red), CD5 (green) and DAPI (blue). Images are at original magnification ×400 (left panel), with a 5× enlargement of the image at right. CD19⁺CD43⁺CD5⁺ B-1a cells are indicated with arrows. Scale bar, 40 μm. (D) B-1a and B-2 cells from the lung of infected WT mice (n = 6) at 4 dpi were sorting purified. Single-cell suspensions were cultured for 16 hours to assess spontaneous IgM secretion. Data are representative of two independent experiments. (E) Shown are the numbers of virus-specific IgM-producing or total IgM-producing B-1a or B-2 cells per 1x10⁴ cells or per lung as detected by ELISPOT in (D) (n = 3). (F) Schematic description of B-1a depletion in mouse models. Female WT mice between 6 to 8-week of age were used to generate B-1a cell-eliminated mice. Mice were full-body irradiated with 956 cGy of Caesium. To construct mice without B-1a cells, 3x10⁶ WT mice-derived bone marrow (BM) cells were injected <i>i</i>.<i>v</i>. <i>via</i> the tail vein into mice 8 hours post irradiation. Control mice were generated by transferring both 3x10⁶ BM cells and 5x10⁶ pleural cavity cells from WT mice. The elimination of B-1a cells was analyzed 2 months after cell transfer. (G) WT and <i>Il17a</i>^-/- mice were infected with H1N1 influenza virus. Infected <i>Il17a</i>^-/- mice were i.v. injected 0.5 ml serum from naïve WT mice, irradiated WT mice reconstituted with BM and cavity cells, or irradiated WT mice reconstituted with only BM cells at 1, 3, 5 dpi. Mice were monitored for their survival rate for 14 successive days. Survival curve was determined using Kaplan-Meier analysis. (n = 7–17). Data are represented as mean ± SEM. *, p < 0.05, **, p < 0.01, ***, p < 0.001.</p

IL-17A deficiency severely impairs early antibody production during influenza infection.

<p>(A) The survival rates of H1N1 influenza virus-infected WT and <i>Il17a</i>^-/- mice were monitored for 14 successive days (n = 23). The survival curve was determined using Kaplan-Meier analysis. (B) Body weight changes of mice in (A) were monitored for 14 successive days (n = 23). (C) The copy number of influenza virus <i>NP</i> gene in the lung tissues at 5dpi was measured by quantitative real-time PCR (n = 6). (D) Representative H&E histology of lung tissues from WT and <i>Il17a</i>^-/- mice were evaluated at 5 dpi following challenge with H1N1 influenza virus. Sections are representative of five mice in each group. Images are at magnification x 200. (E) Combined histological scores of lung sections of infected mice in (D) were determined in a blinded manner according to the relative degree of inflammation and tissue damage. (F) Absolute concentrations of IgM, IgA, and IgG in the bronchoalveolar lavage fluid (BLF) of H1N1 influenza-infected WT mice at different time points were quantified with ELISA assay. Antibody levels at different time points were compared with the control at 0 dpi (n = 12). (G) Total IgM, virus-specific IgM and PC-specific IgM levels in BLF of WT and <i>Il17a</i>^-/- mice were determined during the course of H1N1 influenza virus infection by ELISA assay (n = 6). Data are represented as mean ± SEM. *, p < 0.05, **, p < 0.01, ***, p < 0.001.</p

IL-17A signaling upregulates <i>prdm-1</i> transcription <i>via</i> activating NK-kB binging on the promoter of <i>prdm-1</i> gene.

<p>(A) Putative binding sites of NF-κB on the promoter of <i>prdm-1</i> gene. (B) NF-κB binding on the promoter of <i>prdm-1</i> gene upon stimulation of rmIL-17A (20 ng/ ml) at indicated time points. Data are representative of four independent experiments. (C) Immunofluorescence microscopy shows trans-nucleus location of NF-κB as revealed by fluorescent staining of p65 in sorting purified B-1a cells treated with rmIL-17A (20 ng/ ml) at different time points.</p

IL-17A signaling promotes differentiation and antibody production of B-1a cells.

<p>(A) Flow cytometric analysis of IL-17 receptor A (IL-17RA) and IL-17 receptor C (IL-17RC) expression on pleural B-1a (red line), B-1b (red dashed line) and B-2 (blue line) cells stained with IL-17RA and IL-17RC Abs or isotype control Abs (shaded line). Data are representative of five independent experiments. (B) MFI of IL-17RA and IL-17RC expression on pleural B-1a, B-1b and B-2 cells was determined by flow cytometry. (n = 3) (C) B-1a cells were sorting-purified from pleural cavity of WT mice, and cultured with or without rmIL-17A (20 ng/ ml) for 5 days. Production of total IgM, PC-specific IgM and virus-specific IgM in supernatants of cultured B-1a cells was examined with ELISA assay. Data are representative of five independent experiments (NT, no-treatment). (D) B-1a cells in (C) were subjected to ELISPOT analysis after 5 days of culture. Production of total IgM, PC-specific IgM and virus-specific IgM by B-1a cells was examined by ELISPOT assay. Data are representative of three independent experiments. (E) ELISPOT analysis of total IgM, PC-specific IgM and virus-specific IgM producing B-1a cells as in (D). (F) Sorting purified B-1a cells from pleural cavity of WT mice were cultured with or without rmIL-17A (20 ng/ ml) for 24 hours. Gene expression in B-1a cells was examined with real-time PCR assay. (G) Western blot analysis of Blimp-1 expression in sorting purified cavity B-1a cells treated with rmIL-17A (20 ng/ ml) for different time intervals. (H) Western blot analysis of NF-κB activation in sorting purified cavity B-1a cells treated with rmIL-17A (20 ng/ ml) for different time intervals. Data are represented as mean ± SEM. *, p < 0.05, **, p < 0.01, ***, p < 0.001.</p

Enhanced Immune Response and Protective Effects of Nano-chitosan-based DNA Vaccine Encoding T Cell Epitopes of Esat-6 and FL against <i>Mycobacterium Tuberculosis</i> Infection

<div><p>Development of a novel and effective vaccine against <i>Mycobacterium tuberculosis</i> (<i>M.tb</i>) is a challenging for preventing TB infection. In this study, a novel nanoparticle-based recombinant DNA vaccine was developed, which contains Esat-6 three T cell epitopes (Esat-6/3e) and fms-like tyrosine kinase 3 ligand (FL) genes (termed Esat-6/3e-FL), and was enveloped with chitosan (CS) nanoparticles (nano-chitosan). The immunologic and protective efficacy of the nano-chitosan-based DNA vaccine (termed nano-Esat-6/3e-FL) was assessed in C57BL/6 mice after intramuscular prime vaccination with the plasmids DNA and nasal boost with the Esat-6/3e peptides. The results showed that the immunized mice remarkably elicited enhanced T cell responses and protection against <i>M.tb H37Rv</i> challenge. These findings indicate that the nano-chitosan can significantly elevate the immunologic and protective effects of the DNA vaccine, and the nano-Esat-6/3e-FL is a useful vaccine for preventing <i>M.tb</i> infection in mice.</p></div

B cells loading DRibbles antigen could re-activate effector T cells.

<p>(A) The schematic diagram outlines the experiment protocol. C57/BL6 mice or BALB/c mice were intro-node vaccinated with DRibbles respectively. Lymphocytes were collected from lymph nodes (LN) of vaccinated C57/BL6 mice or BALB/c mice on day 7 after immunization. B cells purified from wide type C57/BL6 mice were stimulated with DRibbles for 6 hours and then washed 3 times with PBS. The lymphocytes were co-incubated with DRibbles or DRibbles-loaded B cells or B cells alone for 72 hours (n = 5). (B) The supernatants were harvested for detection of IFN-γ by ELISA. (C) CD8⁺ T cells were purified from the vaccinated C57/BL6 mice, and then co-incubated with B cells plus DRibbles (with DCs plus DRibbles at 1∶1 ratio or B cell alone as control) at the indicated ratio for 72 hours. IFN-γ in the supernatants was tested via ELISA. (D and E) CD4⁺ T cells were purified from the vaccinated C57/BL6 mice, and then co-incubated with B cells plus DRibbles at the indicated ratio for 72 hours. IFN-γ (D) and IL-4 (E) in the supernatants were tested via ELISA. (F) CD8⁺ T cells purified from the DRibbles-vaccinated C57/BL6 mice were co-incubated at 1∶1 ratio with B cells (from wild type, TLR4-, TLR2- or MyD88-deficient mice) plus DRibbles for 72 hours. IFN-γ in the supernatants was tested via ELISA. (G) CD8⁺ T cells were purified from the Hep1-6-DRibbles vaccinated C57/BL6 mice, and then co-incubated at 1∶1 ratio with B cells plus Hep1-6-, B16F10- or BNL-DRibbles for 72 hours respectively. IFN-γ in the supernatants was tested via ELISA. Data which are presented were obtained as a result of triplicates.</p

The CTL activity of the mice elicited by nano-Esat-6/3e-FL or other plasmids.

<p>Splenocytes from naive mice pulsed with (CFSEhigh) or without (CFSElow) peptides were transferred into the immunized mice. The representative histograms (<b>A</b>) and percentages (<b>B</b>) of specific lysis in the immunized mice were compared. Data are one representative results from three performed experiments, and presented as the mean ± SD (<i>n</i> = 6). <i>NS: P</i>>0.05; *<i>P</i><0.05; ***<i>P</i><0.001 versus the mice treated with nano-chitosan, nano-pIRES or nano-FL plasmids; the other differences among nano-Esat-6/3e-FL, nano-Esat-6/3e, Esat-6/3e-FL, nano-Esat-6, nano-Esat-6-FL and BCG treatments were showed on the figure directly.</p

DRibbles induced proliferation and activation of B cells in vitro.

<p>(A) Purified B cells were labeled with CFSE and then co-incubated with DRibbles (DRs), whole tumor cell lysate (Lys) or LPS for 5 days. The proliferation of B cells was accessed by flow cytometry. (B) Purified B cells were co-incubated with DRibbles for 3 days and collected for staining with the indicated Abs or isotype-matched control Abs (gray filled area). The expression of H2-K^b, I-A^b, CD86 and CD40 on B cells was analyzed by flow cytometry. (C and D) Splenocytes (C) and purified B cells (D) were co-incubated with DRibbles or lysate respectively for 7 days. IgM in the supernatants was analyzed by ELISA. (E) Purified B cells were co-incubated with DRibbles, tumor cell lysate or LPS for 3 days. Cytokines including IL-6, IL-10, TNF-αα in the supernatants was analyzed by ELISA. (CM indicated complete medium). Results represent three independent experiments.</p