SummaryProtein homology studies identified five kinases potentially capable of phosphorylating the Spo0F response regulator and initiating sporulation in Bacillus subtilis. Two of these kinases, KinA and KinB, were known from previous studies to be responsible for sporulation in laboratory media. In vivo studies of the activity of four of the kinases, KinA, KinC, KinD (ykvD) and KinE (ykrQ), using abrB transcription as an indicator of Spo0A,P level, revealed that KinC and KinD were responsible for Spo0A,P production during the exponential phase of growth in the absence of KinA and KinB. In vitro, all four kinases dephosphorylated Spo0F,P with the production of ATP at approximately the same rate, indicating that they possess approximately equal affinity for Spo0F. All the kinases were expressed during growth and early stationary phase, suggesting that the differential activity observed in growth and sporulation results from differential activation by signal ligands unique to each kinase.

In this open-label randomized clinical trial, HLA-identical sibling-matched hematopoietic stem cells (HSC) were transplanted (non-MSCs group, n ¼ 15) or cotransplanted with mesenchymal stem cells (MSCs) (MSCs group, n ¼ 10) in hematologic malignancy patients. The median number of MSCs infused was 3.4 Â 10 5 kg À1 (range, 0.3-15.3 Â 10 5 kg À1 ). MSCs infusions were well tolerated. The median time to neutrophil engraftment (absolute neutrophil count 40.5 Â 10 9 l À1 ) was 16 days for MSCs group and 15 days for non-MSCs group. The median time to platelet engraftment (platelet count 450 Â 10 9 l À1 ) was 30 and 27 days, respectively. Grades II-IV acute graft-versus-host disease (GVHD) was observed respectively, in one (11.1%) and eight (53.3%) evaluable patients. Chronic GVHD was found in one (14.3%) and four (28.6%) evaluable patients. The number of patients who relapsed were six (60.0%) and three (20.0%), and the 3-year disease-free survivals were 30.0 and 66.7%, respectively. Thus cotransplantation of MSCs and HSCs may prevent GVHD, but the relapse rate is obviously higher than the control group. We conclude that use of MSCs must be handled with extreme caution before a large-scale clinical trial is performed.

We recently reported the discovery of AM-8553 (1), a potent and selective piperidinone inhibitor of the MDM2-p53 interaction. Continued research investigation of the N-alkyl substituent of this series, focused in particular on a previously underutilized interaction in a shallow cleft on the MDM2 surface, led to the discovery of a one-carbon tethered sulfone which gave rise to substantial improvements in biochemical and cellular potency. Further investigation produced AMG 232 (2), which is currently being evaluated in human clinical trials for the treatment of cancer. Compound 2 is an extremely potent MDM2 inhibitor (SPR KD = 0.045 nM, SJSA-1 EdU IC50 = 9.1 nM), with remarkable pharmacokinetic properties and in vivo antitumor activity in the SJSA-1 osteosarcoma xenograft model (ED50 = 9.1 mg/kg).

We have previously shown that Toll-like receptor (TLR)-activated murine nonparenchymal liver cells [(NPC); Kupffer cells (KC), liver sinusoidal endothelial cells (LSEC)]T he hepatitis B virus (HBV) is a hepatotropic DNA virus that can lead to chronic hepatitis, which can be complicated by the development of liver cirrhosis and hepatocellular carcinoma. Current approved therapeutic strategies for treatment HBV include interferon-alpha (IFN-␣) and nucleoside and nucleotide analogs. 1,2 However, only a minority of patients that are treated with these agents show a long-term sustained response with "eradication" [for example, hepatitis B surface antigen (HBsAg) loss] of the virus.

Summary Little is known of how the Toll‐like receptor (TLR) system can modulate the function of non‐parenchymal liver cells (NPC) as a major component of the innate and adaptive immune system of the liver. To investigate the diversification of TLR signalling pathways in NPC, we isolated Kupffer cells (KC) and liver sinusoidal endothelial cells (LSEC) from wild‐type C57BL/6 mice and examined their responses to TLR1 to TLR9 agonists. The data show that KC respond to all TLR ligands by producing tumour necrosis factor‐α (TNF‐α) or interleukin‐6 (IL‐6), to TLR3 and TLR4 ligands only by producing interferon‐β (IFN‐β), to TLR1 and TLR8 ligands by significantly up‐regulating major histocompatibility complex (MHC) class II and costimulatory molecules, and to TLR1, ‐2, ‐4 and ‐6 ligands by inducing high levels of T‐cell proliferation and IFN‐γ production in the mixed lymphocyte reaction (MLR). Similarly, LSEC respond to TLR1 to ‐4, ‐6, ‐8 and ‐9 ligands by producing TNF‐α, to TLR3 and ‐4 ligands by producing IL‐6, and to TLR3 ligands by producing IFN‐β. Interestingly, despite significant up‐regulation of MHC class II and co‐stimulatory molecules in response to TLR8 ligands, LSEC stimulated by TLR1, ‐2 or ‐6 could stimulate allogeneic T cells as assessed by MLR. By contrast, myeloid dendritic cells, used as positive control for classical antigen‐presenting cells, respond to TLR1, ‐2, ‐4 and ‐9 ligands by both up‐regulation of CD40 and activation of allogeneic T cells. In conclusion, NPC display a restricted TLR‐mediated activation profile when compared with ‘classical’ antigen‐presenting cells which may, at least in part, explain their tolerogenic function in the liver.

In our effort to develop agents for the treatment of influenza, a phenotypic screening approach utilizing a cell protection assay identified a series of azaindole based inhibitors of the cap-snatching function of the PB2 subunit of the influenza A viral polymerase complex. Using a bDNA viral replication assay (Wagaman, P. C., Leong, M. A., and Simmen, K. A. Development of a novel influenza A antiviral assay. J. Virol. Methods 2002, 105, 105-114) in cells as a direct measure of antiviral activity, we discovered a set of cyclohexyl carboxylic acid analogues, highlighted by VX-787 (2). Compound 2 shows strong potency versus multiple influenza A strains, including pandemic 2009 H1N1 and avian H5N1 flu strains, and shows an efficacy profile in a mouse influenza model even when treatment was administered 48 h after infection. Compound 2 represents a first-in-class, orally bioavailable, novel compound that offers potential for the treatment of both pandemic and seasonal influenza and has a distinct advantage over the current standard of care treatments including potency, efficacy, and extended treatment window.

MicroRNAs (miRNAs) are highly conserved small noncoding RNAs participating in regulation of various cellular processes. Viruses have been shown to utilize cellular miRNAs to increase their replication in host cells. Until now, the role of miRNAs in hepatitis B virus (HBV) replication has remained largely unknown. In this study, a number of miRNA mimics were transfected into hepatoma cell lines with HBV replication. It was noted that microRNA-1 (miR-1) transfection resulted in a marked increase of HBV replication, accompanied with up-regulated HBV transcription, antigen expression, and progeny secretion. However, bioinformatics and luciferase reporter analysis suggested that miR-1 may not target the HBV genome directly but regulate the expression of host genes to enhance HBV replication. Further studies showed that miR-1 was able to enhance the HBV core promoter transcription activity by augmenting farnesoid X receptor a expression. In addition, miR-1 arrested the cell cycle at the G 1 phase and inhibited cell proliferation by targeting histone deacetylase 4 and E2F transcription factor 5. Analysis of the cellular gene expression profile indicated that miR-1 transfected hepatoma cells developed a differentiated phenotype of hepatocytes. Conclusion: MiR-1 regulates the expression of several host genes to enhance HBV replication and reverse cancer cell phenotype, which is apparently beneficial for HBV replication. Our findings provide a novel perspective on the role of miRNAs in host-virus interactions in HBV infection.

In the phosphorelay signal transduction system for sporulation initiation in Bacillus subtilis, the opposing activities of histidine kinases and aspartyl phosphate phosphatases determine the cell's decision whether to continue with vegetative growth or to initiate the differentiation process. Regulated dephosphorylation of the Spo0A and Spo0F response regulators allows a variety of negative signals from physiological processes that are antithetical to sporulation to impact on the activation level of the phosphorelay. Spo0FϳP is the known target of two related phosphatases, RapA and RapB. In addition to RapA and RapB, a third member of the Rap family of phosphatases, RapE, specifically dephosphorylated the Spo0FϳP intermediate in response to competence development. RapE phosphatase activity was found to be controlled by a pentapeptide (SRNVT) generated from within the carboxy-terminal domain of the phrE gene product. A synthetic PhrE pentapeptide could (i) complement the sporulation deficiency caused by deregulated RapE activity of a phrE mutant and (ii) inhibit RapE-dependent dephosphorylation of Spo0FϳP in in vitro experiments. The PhrE pentapeptide did not inhibit the phosphatase activity of RapA and RapB. These results confirm previous conclusions that the specificity for recognition of the target phosphatase is contained within the amino acid sequence of the pentapeptide inhibitor.