Background:We previously identified a synthetic glycolipid (named CCL-34) that activates Toll-like receptor 4 (TLR4). Results: CCL-34 induces cancer cell death via TLR4-dependent activation of immune cells, which requires its sugar moiety. Conclusion: CCL-34 exhibits anticancer immunity via TLR4, and its sugar moiety plays an essential role. Significance: A new TLR4 agonist with anticancer activity and a broadening molecular basis of TLR4-activating glycolipids is revealed.

A new series of monosaccharide-based glycolipids devoid of phosphate groups and with two lipid chains were rationally designed by varying the lipid chain lengths and saccharide structure of a α-GalCer-derived lead compound (CCL-34) that is a potent TLR4 agonist. The NF-κB activity of a 60-membered galactosyl serine-based synthetic library containing compounds with various lipid chain lengths was measured in a HEK293 cell line that stably expressed human TLR4, MD2, and CD14 (293-hTLR4/MD2-CD14). The results showed that the optimal carbon chain lengths for the lipid amine and fatty acid to activate TLR4 were 10-11 and 12, respectively. Evaluation of a 20-membered synthetic glycosyl serine-based lipid library containing compounds with various saccharide moieties and fixed lipid chain lengths revealed that the galactose moiety in CCL-34 could be replaced by glucose without loss of activity (CCL-34-S3 and CCL-34-S16). Changing the orientation of the anomeric glycosidic bond of CCL-34 resulted in a complete loss of activity (β-CCL34). Surprisingly, a change in configuration of the anomeric glycosidic bond in a glucosyl glycolipid is tolerable (CCL-34-S14). Another noteworthy observation is that the activity of a l-fucosyl derived glycolipid (CCL-34-S13) was comparable to that of CCL-34. In sum, this study determines the structural features that are crucial for an optimal TLR4-stimulating activity. It also provides several molecules with immunostimulating potential.

TiO2 sol with steady suspension and high photocatalytic activity was prepared via a precipitation-peptization method. The XRD results indicate that the TiO2 sol exhibited an anatase structure. TiO2 films on woven fabrics (carbon, PET and Nylon), prepared via dip-coating with TiO2 sol, were characterized by XRD and SEM analysis. The dependence of the woven fabrics properties on the amount of TiO2 coated and photocatalytic activity were also studied. When the diameter of fibers is smalle, large quantity of TiO2 is coated on woven fabrics leading to an improvement in the photocatalytic activity. It is observed that the photocatalytic activity of TiO2 film coated on woven fabrics exceeds that of TiO2 film coated on common glass substrate with the same surface area.

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