Regulation of TB Vaccine-Induced Airway Luminal T Cells by Respiratory Exposure to Endotoxin

Tuberculosis (TB) vaccine-induced airway luminal T cells (ALT) have recently been shown to be critical to host defense against pulmonary TB. However, the mechanisms that maintain memory ALT remain poorly understood. In particular, whether respiratory mucosal exposure to environmental agents such as endotoxin may regulate the size of vaccine-induced ALT population is still unclear. Using a murine model of respiratory genetic TB vaccination and respiratory LPS exposure, we have addressed this issue in the current study. We have found that single or repeated LPS exposure increases the number of antigen-specific ALT which are capable of robust secondary responses to pulmonary mycobacterial challenge. To investigate the potential mechanisms by which LPS exposure modulates the ALT population, we have examined the role of ALT proliferation and peripheral T cell recruitment. We have found that LPS exposure-increased ALT is not dependent on increased ALT proliferation as respiratory LPS exposure does not significantly increase the rate of proliferation of ALT. But rather, we find it to be dependent upon the recruitment of peripheral T cells into the airway lumen as blockade of peripheral T cell supplies markedly reduces the initially increased ALT. Thus, our data suggest that environmental exposure to airborne agents such as endotoxin has a profound modulatory effect on TB vaccine-elicited T cells within the respiratory tract. Our study provides a new, M.tb antigen-independent mechanism by which the respiratory mucosal anti-TB memory T cells may be maintained.     

The biological activity of ubiquitinated BoNT/B light chain in vitro and in human SHSY‐5Y neuronal cells

BoNT/B light chain is a zinc‐dependent endopeptidase. After entering its target, the neuronal cell, BoNT/B is responsible for synaptobrevin‐2 (VAMP‐2) cleavage. This results in reduced neurotransmitter (acetylcholine) release from synaptic vesicles, yielding muscular paralysis. Since the toxin persists in neuronal cells for an extended period, regeneration of VAMP‐2 is prevented. We evaluated therapeutic targets to overcome botulinum persistence because early removal would rescue the neuronal cell. The ubiquitination/proteasome cellular pathway is responsible for removing “old” or undesirable proteins. Therefore, we assessed ubiquitination of BoNT/B light chain in vitro, and characterized the effects of ubiquitination modulating drugs, PMA (phorbol 12‐myristate 13‐acetate) and expoxomicin, on ubiquitination of BoNT/B light chain in neuronal cells. Both drugs altered BoNT/B light chain ubiquitination. Ubiquitination in vitro and in cells decreased the biological activity of BoNT/B light chain. These results further elucidate BoNT protein degradation pathways in intoxicated neuronal cells and mechanisms to enhance toxin removal. J. Cell. Biochem. 108: 660–667, 2009. Published 2009 Wiley‐Liss, Inc.     

Structure-guided design and synthesis of isoflavone analogs of GW4064 with potent lipid accumulation inhibitory activities

Our group has previously reported a series of isoflavone derivatives with antidyslipidemic activity. With this background, a series of isoflavone analogs of GW4064 were designed, synthesized and evaluated the lipid-lowering activity of analogs. As a result, most of compounds significantly reduced the lipid accumulation in 3T3-L1 adipocytes and four of them (10a, 11, 15c and 15d) showed stronger inhibitory than GW4064. The most potent compound 15d exhibited promising agonistic activity for FXR in a cell-based luciferase reporter assay. Meanwhile, 15d up-regulated FXR, SHP and BSEP gene expression and down-regulated the mRNA expression of lipogenesis gene SREBP-1c. Besides, an improved safety profile of 15d was also observed in a HepG2 cytotoxicity assay compared with GW4064. The obtained biological results were further confirmed by a molecular docking study showing that 15d fitted well in the binding pocket of FXR and interacted with some key residues simultaneously.     

A novel “trifunctional protease” with reducibility,hydrolysis, and localization used for wool anti-felting treatment

Proteases can cause unacceptable fiber damage when they are singly applied to wool anti-felting treatment which can make wool textiles machine-washable. Even if protease is attached by synthetic polymers, the modified protease plays a limited role in the degradation of keratin with dense structure consisting of disulfide bonds in the scales. Here, to obtain “machine-washable” wool textiles, a novel “trifunctional protease” with reducibility, hydrolysis, and localization is developed by means of covalent bonding of protease molecules with poly (ethylene glycol) bis (carboxymethyl) ether (HOOC-PEG-COOH) and l-cysteine using carbodiimide/N-hydroxysuccinimide (EDC/NHS) coupling, aiming at selectively degrading the scales on the surface of wool. The formation of polymer is confirmed with size exclusion chromatography (SEC) and Fourier transform infrared spectroscopy (FT-IR). Ellman’s test and fluorescence microscopy reveal that the modified protease can reduce disulfide bonds and restrict hydrolysis of peptide bonds on the wool scales. Furthermore, when applied to wool fabrics, the modified protease reach better treatment effects considering dimensional stability to felting (6.12%), strength loss (11.7%) and scale dislodgement proved by scanning electron microscopy (SEM), alkali solubility, wettability, and dyeability. This multifunctional enzyme is well-designed according to the requirement of the modification of wool surface, showing great potential for eco-friendly functionalization of keratin fibers rich in disulfide linkage.

     

天然多糖——几丁/壳聚糖在烟草工业上的应用——新型高效吸附剂的研究初探

二 将壳聚糖微粒化,用于香烟的过滤咀中,利用壳聚糖的吸附特性,测定其对烟气中的总粒相物及植物碱的吸附能力,比较其与醋酸纤维吸附能力的大小,得到令人欣喜。的结果。     

A potential model for studying the plasticity and reprogramming of human epidermal stem cells through preimplantation blastocyst microinjection

Microinjection of adult stem cells (ASCs) into blastocysts provides a classic model for studying ASC plasticity. To explore the molecular mechanisms that govern the reprogramming of ASCs, we evaluated the experimental model through microinjection of human epidermal stem cells (hEpiSCs) into mouse blastocysts. Mouse blastocysts underwent regular embryogenesis after microinjection of allogeneic cells, confirmed by morphological observation and embryo cell counting. hEpiSCs survive and integrate into mouse embryos, by monitoring the migration of injected cells at 2, 4, 12, 16 and 24 h. In this xenogeneic system, hEpiSCs could be reprogrammed within 24 h, as evidenced by the silencing of CK15 and Integrin beta 1 gene expression, without activation of Oct4 and Nanog. Microinjection of hEpiSCs into mouse blastocysts provides an efficient model for studying the molecular mechanisms of their plasticity. Moreover, the possibility of inducing pluripotent stem cells without transgenes or viruses can be entertained.     

Effects of cutinase on the enzymatic shrink-resist finishing of wool fabrics

A novel microbial cutinase from Thermobifida fusca WSH04 was applied in the pretreatment of wool fabrics followed by protease treatment, aiming at improving the wettability of the samples by hydrolyzing the outmost bound lipids in the wool surface. Cutinase pretreatment could increase the efficacy of the subsequent protease treatment by improving the wettability, dyeability, and shrink-resistance of the wool fabrics. The data obtained by the XPS method showed the changes of elemental concentration in the wool surface after cutinase pretreatment. Compared with the fabrics treated with hydrogen peroxide and protease, the combination of cutinase and protease treatments produced better results in terms of wettability and shrink-resistance with less strength loss. The anti-felting property of the fabrics treated with the enzymatic resist-shrink technique is very promising to meet the commercial standard.