The first example of room temperature homogeneous non-noble metal catalyzed selective N-alkylation of anilines with alcohols using bis-NHC manganese.

CpG DNA ͉ cytokines ͉ immune stimulation ͉ innate immunity ͉ immunotherapy

Viral and synthetic single-stranded RNAs are the ligands for Tolllike receptor (TLR)7 and TLR8. However, single-stranded RNA is rapidly degraded by ubiquitous RNases, and the studies reported to date have used RNA with lipid carriers. To overcome nuclease susceptibility of RNA, we have synthesized several RNAs incorporating a range of chemical modifications. The present study describes one pool of RNA compounds, referred to as stabilized immune modulatory RNA (SIMRA) compounds, in which two RNA segments are attached through their 3 ends. SIMRA compounds showed greater stability in human serum compared with linear RNA and activated human TLR8, but not TLR7, in HEK293 cells without using lipid carriers. Interestingly, another set of SIMRA compounds containing 7-deazaguanosine substituted for natural guanosine activated human TLR7 and TLR8. Additionally, TLR7-and TLR8-activating compounds, but not the compounds that activated only TLR8, stimulated mouse immune cells in vitro and in vivo and produced dose-dependent T helper 1-type cytokines. Both types of compounds activated human peripheral blood mononuclear cells, but only TLR7-and TLR8-activating compounds activated plasmacytoid dendritic cells and produced high levels of IFN-␣. In monkeys, s.c. administration of both types of SIMRA compounds induced transient changes in peripheral blood monocytes and neutrophils, and activated T lymphocytes, monocytes, and NK cells. Both types of compounds induced IFN-␥-inducible protein 10, but only the 7-deazaguanosine-containing compound that activated both TLR7 and TLR8 induced IFN-␣ in monkeys. This is a comprehensive study of RNA-based compounds containing structures and synthetic stimulatory motifs in mouse, monkey, and human systems without using lipid carriers. oligoribonucleotides T oll-like receptors (TLRs) recognize specific molecular signatures called pathogen-associated molecular patterns present within pathogens (1). Eleven TLRs (TLR1-TLR11) have been identified in mammals that recognize different pathogen-associated molecular patterns present in bacteria and viruses. Among the 11 TLRs, TLRs 3, 7, 8, and 9 are present on the membranes of endosomes in the cells and detect nucleic acid molecular patterns of intracellular DNA and RNA pathogens (2-7). The other TLRs are present on the cell surface and recognize molecular patterns associated with extracellular pathogens. Synthetic and bacterial DNA containing unmethylated CpG motifs are the ligands for TLR9 (7). Viral and synthetic double-stranded RNAs are the ligands for TLR3 (2). Viral and synthetic single-stranded RNAs are the ligands for TLR7 and TLR8 (4-6). Imidazoquinoline-based small molecules and certain guanosine-based nucleosides also have been shown to act as ligands for TLR7 and TLR8 (3).In addition to the differences in the cellular localization of TLRs, different immune cell subtypes express different TLRs (8). For example, TLRs 7 and 9 are expressed in human plasmacytoid dendritic cells (pDCs) and B cells, and TLR8 is expressed in human myeloid dendritic...

IntroductionTherapeutic potentials of mesenchymal stem cells (MSCs) from different sources have been evaluated in pre-clinical and clinical settings. Although MSCs from different sources share MSC-specific characteristics and functions, inconsistent or controversial results of pre-clinical and clinical applications of such cells are frequently reported. This may be partially due to the fact that MSCs isolated from different origins may differentially express some functions not typical for MSCs, and hence have different therapeutic potentials. The aim of this study is to investigate the differences in human placental MSCs (P-MSCs) of fetal and maternal origins in the aspects of clinical importance.MethodsP-MSCs of fetal and maternal origins isolated from normal term placentas were characterized for their typical phenotype as well as their expression of receptors and growth factors of clinic interests. P-MSCs that preferentially express hepatocyte growth factor (HGF) and CD200 were evaluated for their therapeutic potentials in models of angiogenesis and allogeneic skin transplantation, in comparison with their HGF and CD200 negative partners.ResultsAlthough all P-MSCs express typical MSC phenotype, fetal but not maternal P-MSCs express high levels of CD200 and HGF. Compared with HGF and CD200 negative P-MSCs, HGF and CD200 positive cells demonstrated significantly high potentials in promoting angiogenesis in vitro and increasing immunosuppressive function in vivo. These therapeutic potentials were at least in part due to their differences in HGF and CD200 expression, respectively.ConclusionsWe conclude that MSC origins may have significant impact on the therapeutic potentials of such cells, and should be taken into consideration in clinical applications.