Conjugated linoleic acid (CLA) is found naturally in dairy and beef products at levels of 0.2% to 2% of the total fat. A more concentrated source of dietary CLA, low in saturated fat, would be highly desirable to obtain optimum CLA levels of about 3 g/d. We recently reported photoisomerization of soy oil with iodine catalysis to be a simple way of producing CLA in laboratory without high-energy input or expensive enzymes and microorganisms. However, a long irradiation time of 144 h has been a limitation for this technique to be of practical value. The objectives of this study were to build a pilot plant unit to rapidly produce high-CLA soy oil by photoirradiation and optimize the processing parameters to obtain high-CLA soy oil. Degassed oil with dissolved-iodine catalyst was irradiated by UV lamps in an illuminated laminar flow unit (ILFU). The ILFU consists of 2 borosilicate glass plates in a silicone lined stainless steel frame. The static mode of operation yielded 5.7% of total CLA isomers and performed twice as well than the continuous mode with 2.5% of total CLA. Irradiating oil in a static mode with reflective surfaces increased the CLA yields 3-fold to 16.4%. About 22% of total CLA isomers can be rapidly produced from soy oil linoleic acid with 0.35% iodine catalyst in a 0.5-cm-thick oil layer maintained at 48 degrees C for 12 h. The peroxide value and GC-MS analysis did not identify any volatile compounds characteristic of lipid oxidation. This study is a definitive step toward the commercialization of large-scale production of CLA-rich soy oil.

The major and minor fimbriae proteins produced by the human pathogen Porphyromonas gingivalis are required for invasion of human aortic endothelial cells and for the stimulation of potent inflammatory responses. In this study, we report that native forms of both the major and minor fimbriae proteins bind to and signal through TLR2 for this response. Major and minor fimbriae bound to a human TLR2:Fc chimeric protein with an observed Kd of 28.9 nM and 61.7 nM, respectively. Direct binding of the major and minor fimbriae to a human chimeric CD14-Fc protein also established specific binding of the major and minor fimbriae to CD14 with classic saturation kinetics. Using a P. gingivalis major and minor fimbriae mutant, we confirmed that TLR2 binding in whole cells is dependent on the expression of the major and minor fimbriae. Although we did not observe binding with the major or minor fimbriae to the TLR4-Fc chimeric protein, signaling through TLR4 for both proteins was demonstrated in human embryonic kidney 293 cells transfected with TLR4 and only in the presence MD-2. Transient transfection of dominant-negative forms of TLR2 or TLR4 reduced IL-8 production by human aortic endothelial cells following stimulation with major or minor fimbriae. The ability of two well-defined microbe-associated molecular patterns to select for innate immune recognition receptors based on accessory proteins may provide a novel way for a pathogen to sense and signal in appropriate host environments.

Daily intake of conjugated linoleic acid (CLA), an anticarcinogenic, antiatherosclerotic, antimutagenic agent, and antioxidant, from dairy and meat products is substantially less than estimated required values. The objective of this study was to obtain CLA-rich soybean oil by a customized photochemical reaction system with an iodine catalyst and evaluate the effect of processing on iodine and iodo compounds after adsorption. After 144 h of irradiation, a total CLA yield of 24% (w/w) total oil was obtained with 0.15% (w/w) iodine. Trans,trans isomers (17.5%) formed the majority of the total yield and are also associated with health benefits. The isomers cis-9,trans-11 and trans-10,cis-12 CLA, associated with maximum health benefits, formed approximately 3.5% of the total oil. This amount is quite significant considering that total CLA obtained from dairy sources is only 0.6%. ATR-FTIR, 1H NMR, and GC-MS analyses indicated the absence of peroxide and aldehyde protons, providing evidence that secondary lipid oxidation products were not formed during the photochemical reaction. Adsorption processing vastly reduced the iodine and iodocompounds without CLA loss. Photocatalysis significantly increased the levels of CLA in soybean oil.

IntroductionRecognition of bacterial lipopolysaccharides (LPSs) by mammalian cells depends upon the presence of both Toll-like receptor 4 (TLR4; CD284) and MD-2 (Ly96). 1-3 TLR4 is a 110-kDa type I integral membrane glycoprotein characterized by the presence of multiple leucine-rich repeats (LRRs) on its ectodomain and a signaling Toll-interleukin-1 receptor resistance (TIR) domain on the cytoplasmic side. MD-2 is a 25-to 30-kDa secreted glycoprotein which belongs to the MD-2-lipid binding (ML) family of single-domain lipid-binding secreted proteins. 4 MD-2 binds noncovalently to the extracellular domain of TLR4, 5 and is tethered on the surface of cells expressing TLR4. 6 The apparent K d of this interaction, as determined for human MD-2/TLR4, is approximately 12 nM. 7 In addition to binding to TLR4, MD-2 binds specifically to the lipid portion of LPS (lipid A). Lipid A from enterobacteriaceae is a collection of phosphorylated glucosaminebased saccharolipids with up to 7 acyl moieties. This highly hydrophobic structure anchors LPS to the outer leaflet of the cell wall of 8 and is the epitome of an innate immune stimulator. The crystal structures of MD-2 bound to 2 antagonistic tetracylated lipid A structural analogs (lipid IVa and eritoran) reveal that MD-2 interacts with its ligands via a hydrophobic pocket that can accommodate at least 4 acyl chains without entailing any conformational change. 5,9-11 When complexes of MD-2 and TLR4, but not TLR4 alone, are incubated with purified LPS, they produce stable dimers. 5,12 Consistently, cells expressing TLR4 are activated by purified LPS only when MD-2 is provided as a recombinant protein or a transgene, suggesting that TLR4 activation is downstream from an MD-2-dependent signal that induces its aggregation. 11,13,14 The most likely scenario for TLR4 activation is that LPS moves from the surface of Gram-negative bacteria to soluble or TLR4-bound MD-2. This movement is promoted by the lipotransferases LPS-binding protein (LBP) and CD14. Although LBP and CD14 together may enhance the sensitivity to LPS, neither protein is absolutely required for LPS responses, as cellular activation is reliably observed when a sufficiently high concentration of LPS is used. 15 When a phagocyte encounters a Gram-negative cell wall, such high concentrations of LPS are likely. Hence, we speculated that MD-2 might bind to live bacteria and affect the activity of TLR4 on the surface of engaged phagocytes.In an article recently published in this journal, Tissieries et al reported that MD-2 is an acute phase reactant and binds to heat killed Escherichia coli. 16 In the present work, we confirm and extend these observations by presenting a thorough analysis of the binding of MD-2 to live Gram-negative bacteria, and by elucidating the role of the MD-2/TLR4 signaling axis during internalization and killing. Methods Miscellaneous reagents, recombinant proteins, and antibodiesUnless otherwise specified, reagents were purchased from Sigma-Aldrich (St Louis, MO). LPS (E coli 0111:B4) was repurifie...