Response to immune complex vaccine in chronic hepatitis B patients is associated with lower baseline level of serum IgG galactosylation.

The composition of glycan in immunoglobulin G (IgG) has shown to affect various diseases and can be regulated by drugs and preventive vaccination. A hepatitis B surface antigen (HBsAg)-hepatitis B immunoglobulin (HBIG) immune complex (YIC) therapeutic vaccine for chronic hepatitis B (CHB) patients has undergone clinical trials. To explore for markers of CHB, which could be associated with responsiveness to YIC therapeutic vaccine, serum IgG glycosylation in CHB patients was analyzed.

Decreased expression of hepatocyte nuclear factor 4α (Hnf4α)/microRNA-122 (miR-122) axis in hepatitis B virus-associated hepatocellular carcinoma enhances potential oncogenic GALNT10 protein activity.

MicroRNA-122 (miR-122), a mammalian liver-specific miRNA, has been reported to play crucial roles in the control of diverse aspects of hepatic function and dysfunction, including viral infection and hepatocarcinogenesis. In this study, we explored the clinical significance, transcriptional regulation, and direct target of miR-122 in hepatitis B virus (HBV)-associated hepatocellular carcinoma. Reduced expression of miR-122 in patients with HBV-associated hepatocellular carcinoma was correlated with venous invasion and poor prognosis.

Estrogen receptor α (ERα) mediates 17β-estradiol (E2)-activated expression of HBO1.

Background: HBO1 (histone acetyltransferase binding to ORC1) is a histone acetyltransferase (HAT) which could exert oncogenic function in breast cancer. However, the biological role and underlying mechanism of HBO1 in breast cancer remains largely unknown. In the current study, we aimed to investigate the role of HBO1 in breast cancer and uncover the underlying molecular mechanism.

Cyclin G associated kinase interacts with interleukin 12 receptor beta2 and suppresses interleukin 12 induced IFN-gamma production.

Interleukin 12 receptor beta1 (IL-12Rbeta1) and beta2 (IL-12Rbeta2) constitute the functional and high-affinity receptor complex for interleukin 12 (IL-12) and mediate important functions in activated T cells. In this study, we identified cyclin G associated kinase (GAK) as a new IL-12Rbeta2-interacting protein using yeast two-hybrid system and confirmed it by coimmunoprecipitation assays. Overexpression of GAK in activated T cells suppresses IL-12 induced IFN-gamma production but has no detectable effects on its proliferation, whereas knockdown of GAK by RNA interference (RNAi) increases IFN-gamma production.

Specific immune response to HBsAg is enhanced by beta-glucan oligosaccharide containing an alpha-(1-->3)-linked bond and biased towards M2/Th2.

Vaccination with Hepatitis B surface antigen (HBsAg) is being used to prevent HBV infection. The fact that 10% of vaccinees fail to develop protective antibodies has fostered a large body of research for more effective vaccination strategies. Search for new adjuvant, able to selectively trigger protective antibody production, is one of the most promising approaches.

Studies on the Method for the Determination of beta1-4 Galactosyltransferase and Its Kinetics.

A fluorescence assay method for beta1-4galactosyltransferase (beta1-4GT) has been developed involving a pyridylaminated sugar as an acceptor substrate, a fluorescent sugar chain, with the reducing end of the Gnbeta1 - 2Malpha1 - 6(Gnbeta1-2Malpha1-3)Mbeta1 - 4Gnbeta1 - 4Gn - PA aminated with 2-aminopyridine. Microsome was prepared from the liver of normal male rats as an enzyme sample. Then the fluorescent reaction product was separated by reverse-phase HPLC.

Regulatory Effect of All-trans Retinoic Acid (ATRA) on the Activities of N-acetylglucosaminyl Transferase (GnT) III, IV in HL-60 Cells.

The regulatory effect of all-trans retinoic acid (ATRA) on the activities of N-acetylglucosaminyl transferase (GnT) III and IV in HL-60 Cells were studied. It was found that the activities of GnT-III and GnT-IV were significantly decreased by 0.1 &mgr;M ATRA, but not further decreased with the increase in concentration of ATRA to 1.

Studies on the beta(l-4)Galactosyltransferase of Cell Surface in Induced HL60 Cells.

A fluorescene assay method for beta(1-4) galactosyltransferase (beta1-4GT) of cell surface has been developed using a pyridylaminated sugar as an acceptor substrate. A fluorescent sugar chain, whose reducing end of the Gnbeta1-2Malpha1-6(Gnbeta1-2Malpha1-3) Mbeta1-4Gnbeta1-4(Fucalpha1-6) Gn has been aminated with 2-aminopyridine. beta1-4GT activity of cell surface varied in different stages of the cell cycle with the highest activity at interphase.

The regulation of N-Acetylglucosaminyl Transferase III by Protein Kinase C.

The activity of N-acetylglucosaminyl transferase III (GnT III) in 7721 human heptocarcinoma cell was inhibited by two non-specific Ser/Thr protein kinase inhibitors, quercetin and trifluoperazine, and two PKC specific inhibitors, D-sphingosine and staurosporine. The change of GnT III activity paralleled that of membranous PKC (m-PKC) when the cells were treated with PMA, but not with that of cytosolic PKC (c-PKC). Quercetin, D-sphingosine and staurosporine also blocked the PMA activation of GnT-III.

Changes in Glycosylation Alter the Affinity of the Human Transferrin for Its Placental Receptor.

By using serial lectin-Sepharose affinity chromatography (ConA, DSA, and LCA), the transferrins carrying the biantennary complex type of oligosaccharides from sera of healthy individuals and those carrying multiantennary oligosaccharides from sera of pregnant women were purified. The two kinds of transferrins were used to study their binding affinity for isolated placental transferring receptor. The results showed that the binding affinity of the highly branched transferring decreased to half of that for the biantennary type with a K(d) of 9.