Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that plays a pivotal role in several immunoinflammatory and autoimmune diseases. In this study we examined the role of MIF in the development of immunoinflammatory diabetes induced in susceptible strains of mice by multiple low doses of streptozotocin. We found that MIF protein was significantly elevated in islet cells during the development of diabetes, and that targeting MIF activity with either neutralizing antibody or the pharmacological inhibitor (S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester, markedly reduced clinical and histopathological features of the disease, such as hyperglycemia and insulitis. Lymphocytes from mice treated with the MIF inhibitors exhibited reduction of both islet antigen-specific proliferative responses and adhesive cell-cell interactions. Neutralization of MIF also down-regulated the ex vivo secretion of the proinflammatory mediators, TNF-alpha, interferon-gamma, and nitric oxide, while augmenting that of the antiinflammatory cytokine, IL-10. This study provides the first in vivo evidence for a critical role for MIF in the immune-mediated beta-cell destruction in an animal model of human type 1 diabetes mellitus and identifies a new therapeutic strategy for the prevention and treatment of this disease in humans that is based on the selective inhibition of MIF activity.

BackgroundTerpenoids constitute a large family of natural products, attracting commercial interest for a variety of uses as flavours, fragrances, drugs and alternative fuels. Saccharomyces cerevisiae offers a versatile cell factory, as the precursors of terpenoid biosynthesis are naturally synthesized by the sterol biosynthetic pathway.ResultsS. cerevisiae wild type yeast cells, selected for their capacity to produce high sterol levels were targeted for improvement aiming to increase production. Recyclable integration cassettes were developed which enable the unlimited sequential integration of desirable genetic elements (promoters, genes, termination sequence) at any desired locus in the yeast genome. The approach was applied on the yeast sterol biosynthetic pathway genes HMG2, ERG20 and IDI1 resulting in several-fold increase in plant monoterpene and sesquiterpene production. The improved strains were robust and could sustain high terpenoid production levels for an extended period. Simultaneous plasmid-driven co-expression of IDI1 and the HMG2 (K6R) variant, in the improved strain background, maximized monoterpene production levels. Expression of two terpene synthase enzymes from the sage species Salvia fruticosa and S. pomifera (SfCinS1, SpP330) in the modified yeast cells identified a range of terpenoids which are also present in the plant essential oils. Co-expression of the putative interacting protein HSP90 with cineole synthase 1 (SfCinS1) also improved production levels, pointing to an additional means to improve production.ConclusionsUsing the developed molecular tools, new yeast strains were generated with increased capacity to produce plant terpenoids. The approach taken and the durability of the strains allow successive rounds of improvement to maximize yields.

BACKGROUND: Vegetable oil-based polyols are a new class of renewable materials. The structure of oil-based polyols is very different from that of petrochemical polyols, and it is closely related to the structure of oils. The objective of this work was to analyze the structural heterogeneity of soy-based polyols and its effect on the properties of polyols and polyurethanes. RESULTS:A series of polyols with a range of hydroxyl numbers were prepared by hydroformylation and partial esterification of hydroxyls with formic acid. Polyols were reacted with diphenylmethane diisocyanate to obtain polyurethanes of different crosslinking density. Gelation was simulated using the Monte Carlo method with a calculated distribution of functionalities for each polyol.CONCLUSIONS: Most polyols are powerful crosslinkers since weight average functionality varied from 5 to 2.5 resulting in gel points from 53 to 83% conversion. Heterogeneity of polyols had a negative effect on mechanical properties of rubbery polyurethanes and this should be taken in account when designing polyols for flexible applications. This effect was not pronounced in glassy polyurethanes.

Triols of molecular weights (MWs) 1000-4000, suitable for flexible foams, were prepared by transesterification of methyl esters of ricinoleic acid with trimethylol propane. These polyols were noncrystallizing, relatively low-viscosity liquids. They were reacted with diphenylmethane diisocyanate (MDI) to obtain elastomers having glass transition temperatures below 2608C. Polymer networks from high-MW polyols exhibited relatively high sol fractions suggesting that some cyclization occurred during polyol preparation. The low Shore hardness, relatively low strength and modest elongation of the elastomers were attributed to the specific structure of polyricinoleic chains and the presence of dangling chains, serving as plasticizers.

Although astrocytes presumably participate in maintaining the immune privilege of the central nervous system (CNS), the mechanisms behind their immunoregulatory properties are still largely undefined. In this study, we describe the development of regulatory T cells upon contact with astrocytes. Rat T cells pre-incubated with astrocytes completely lost the ability to proliferate in response to mitogenic stimuli. The cells were blocked in G0/G1 phase of the cell cycle, expressed less IL-2R, and produced significantly lower amounts of interferon-gamma (IFN-gamma), but not interleukin-2 (IL-2), IL-10, or tumor necrosis factor (TNF). These anergic cells completely prevented mitogen-induced growth of normal T lymphocytes, as well as CNS antigen-driven proliferation of autoreactive T cells. The suppressive activity resided in both CD4+ and CD8+ T-cell compartments. Heat-sensitive soluble T-cell factors, not including transforming growth factor-beta (TGF-beta) or IL-10, were solely responsible for the observed suppression, as well as for the transfer of suppressive activity to normal T cells. The administration of astrocyte-induced regulatory T cells markedly alleviated CNS inflammation and clinical symptoms of CNS autoimmunity in rats with experimental allergic encephalomyelitis. Finally, the cells with suppressive properties were readily generated from human lymphocytes after contact with astrocytes. Taken together, these data indicate that astrocyte-induced regulatory T cells might represent an important mechanism for self-limitation of excessive inflammation in the brain.