Orthogonal Glycosylation with Phosphate Acceptors for Expeditious Synthesis of Bacterial Inner Core Oligosaccharides.

We report a practical one-pot glycosylation strategy for synthesis of bacterial inner core oligosaccharides that composed of unavailable L-glycero-D-manno and D-glycero-D-manno-heptopyranose components. The glycosylation method features a new orthogonal glycosylation procedure; whereby a phosphate acceptor is coupled with a thioglycosyl donor producing a disaccharide phosphate, which can be engaged in another orthogonal glycosylation procedure to couple with a thioglycosyl acceptor. The phosphate acceptors used in above one-pot procedure are directly prepared from thioglycosyl acceptors via the in-situ phosphorylation. Such phosphate acceptor preparation protocol eliminates the traditional protection and deprotection procedures. Based on the new one-pot glycosylation strategy, two partial inner core structures of Yersinia pestis lipopolysaccharide and Haemophilus ducreyi lipooligosaccharide were acquired.

Genome Sequence of Cluster BI1 Streptomyces griseus Phage TaidaOne.

Bacteriophage TaidaOne was isolated from soil collected in Taipei, Taiwan, using the host Streptomyces griseus. It is a siphovirus with a 56,183-bp genome that contains 86 protein-coding genes. Based on gene content similarity, it was assigned to actinobacteriophage subcluster BI1, within which only TaidaOne and GirlPower genomes contain an acetyltransferase homolog gene.

Cascade In Situ Phosphorylation and One-Pot Glycosylation for Rapid Synthesis of Heptose-Containing Oligosaccharides.

We report a one-pot glycosylation strategy for achieving rapid syntheses of heptose (Hep)-containing oligosaccharides. The reported procedure was designed to incorporate an in situ phosphorylation step into an orthogonal one-pot glycosylation. Hep-containing oligosaccharides were assembled directly from building blocks with minimal effort expended on manipulation of protecting and aglycone leaving groups. The utility of our one-pot procedure was illustrated by synthesizing partial core oligosaccharide structure present in the lipopolysaccharide of Ralstonia solanacearum.

General Homologation Strategy for Synthesis of L-glycero- and D-glycero-Heptopyranoses.

A general and stereospecific homologation strategy for the synthesis of heptopyranosides is reported. The strategy employs the Wittig olefination and proline-catalyzed α-aminoxylation to achieve one carbon elongation and stereoselective hydroxylation at the C6 position, respectively. The L-glycero- and D-glycero-heptopyranosides can be obtained with nearly perfect stereoselectivity. Further study reveals the difference in the chemical shift of the C6 proton of L/D-glycero-heptopyranosyl diastereomers, which is found to be useful for assignment of the configuration of heptopyranosides.

A concise synthesis of single components of partially sulfated oligomannans.

A concise synthesis of single components of C2 sulfated oligomannans including trimers, tetramers, and pentamers is reported. The synthesis features the application of the DMF-modulation method for the participatory thiomannoside donors in 1,2-transα-glycosidic bond formation. The obtained oligomannans were fully characterized using (1)H, (13)C, COSY, and HSQC NMR spectroscopy.

Phenotypic analysis of tumor-infiltrating lymphocytes in hepatocellular carcinoma.

BACKGROUND/AIMS: Tumor may induce local immunosuppression and make the tumor-infiltrating lymphocytes (TILs) functionally inhibited and lose the antitumor effects. Therefore, we did the phenotypic analysis of TILs in hepatocellular carcinoma (HCC) tissues. METHODOLOGY: Lymphocytes were isolated from paired HCC tissues (TILs) and the corresponding non-tumor liver tissues (non-tumor-liver infiltrating lymphocytes, NILs) of 28 patients and were subjected to flow cytometric analysis. RESULTS: Compared with the non-tumor portion, HCC tissues had less intensity of lymphocyte infiltration. TILs had higher CD3+/CD56+ ratio than NILs. Around 70%-90% NILs or TILs expressed the antigen-experienced or memory phenotypes. Around 60%-70% CD4+ or CD8+ NILs and TILs expressed the activation markers CD69 and HLA-DR. However, we found that CD25 is under-expressed in both the CD8+ NILs and TILs. In addition, more percentage of CD4+ CD25+ T cells was detected in the TILs than in the NILs. CONCLUSIONS: HCC tissues had less lymphocytes infiltration. Most of infiltrating lymphocytes from the HCC tissues and the corresponding non-tumor liver tissues were activated and expressed antigen-experienced phenotypes. However, the CD25 was underexpressed in the CD8+ TILs and the CD4+ CD25+ T cells were increased in the TILs. These factors might impair the antitumor immunity in HCCs.

Decreased expressions of hepsin in human hepatocellular carcinomas.

BACKGROUND/AIMS: Hepsin is a type II transmembrane protein predominantly expressed in the liver and has been implicated in participation in blood coagulation pathway and epithelial carcinogenesis. The aim of this current study is to investigate the role of hepsin in hepatocarcinogenesis. METHODS: Quantitative real-time RT-PCR was used to investigate the expression levels of hepsin in a total of 50 paired hepatocellular carcinomas (HCCs) and the corresponding non-tumor liver tissues. Hepsin was transfected to the hepsin-non-expressing SK-HEP-1 cells to study the change of cell proliferation. RESULTS: In 62% (31/50) patients, the expression levels of hepsin in non-tumor liver tissues are at least twofold higher than those in the corresponding HCC tissues. Positive hepatitis B surface antigen was more often detected in patients with hepsin underexpressed in the HCC tissues (74.2% vs. 31.6%, P=0.007). Patients with hepsin underexpressed in the HCC tissues survived shorter time than those without hepsin underexpression in the HCC tissues. The cell proliferation and for a colony formation of SK-HEP-1 HCC cells were inhibited by hepsin. CONCLUSIONS: Most HCC patients had hepsin underexpressed in the HCC tissues. These patients survived for a shorter time compared with those without hepsin underexpression in the HCC tissues. Hepsin expression could inhibit cell proliferation and colony formation of HCC cells.