Nanocapsules incorporating IgG Fc-binding domain derived from Staphylococcus aureus protein A for displaying IgGs on immunosensor chips.

To enhance the sensitivities and antigen-binding capacities of immunosensors, oriented immobilization of antibodies on the surface of the sensor chip is critical, but to date, this has not been adequately achieved. We describe a way of adsorbing immunoglobulin (Ig) proteins onto 32-nm bio-nanocapsules (BNCs) through IgG Fc-binding domains derived from Staphylococcus aureus protein A (ZZ-BNC). This arrangement permits approximately 60 molecules of mouse total IgG bind to ZZ-BNC and all the IgG Fv regions to be displayed outwardly for the effective binding of antigens.

Bionanocapsule-based enzyme-antibody conjugates for enzyme-linked immunosorbent assay.

Macromolecules that can assemble a large number of enzyme and antibody molecules have been used frequently for improvement of sensitivities in enzyme-linked immunosorbent assays (ELISAs). We generated bionanocapsules (BNCs) of approximately 30nm displaying immunoglobulin G (IgG) Fc-binding ZZ domains derived from Staphylococcus aureus protein A (designated as ZZ-BNC). In the conventional ELISA using primary antibody and horseradish peroxidase-labeled secondary antibody for detecting antigen on the solid phase, ZZ-BNCs in the aqueous phase gave an approximately 10-fold higher signal.

In vivo delivery of bionanocapsules displaying Phaseolus vulgaris agglutinin-L4 isolectin to malignant tumors overexpressing N-acetylglucosaminyltransferase V.

Metastasis is a key aspect of tumor malignancy, and several malignant tumors show expression of various mature N-type glycans. In particular, beta1-6 branching N-acetylglucosamine (GlcNAc) is abundantly expressed as a part of high-mannose glycans in various highly metastatic cancers. Phaseolus vulgaris agglutinin-L(4) isolectin (L(4)-PHA), which adheres to beta1-6 GlcNAc specifically, has been used for in situ cancer diagnosis.

Inhibition of measles virus and subacute sclerosing panencephalitis virus by RNA interference.

Subacute sclerosing panencephalitis (SSPE) is a rare, but fatal outcome of measles virus (MeV) infection. SSPE develops after prolonged persistence of mutated MeV called SSPE virus. Although a combination therapy using interferon and inosiplex or ribavirin appears to prolong survival time to some extent, there is currently no effective treatment to completely cure SSPE and a new treatment strategy is greatly needed.

Nonstructural proteins 4A and 4B of hepatitis C virus transactivate the interleukin 8 promoter.

Interleukin 8 (IL-8) is induced in many cell types by various stimuli including virus infection. It was reported that nonstructural protein 5A (NS5A) of hepatitis C virus (HCV) was involved in induction of IL-8 expression at both mRNA and protein levels in cultured human cells. In this study, we aimed to determine whether or not another HCV protein(s) transactivates the IL-8 gene expression, by means of an IL-8 promoter-driven luciferase reporter assay and measurement of endogenous IL-8 mRNA and secreted IL-8 protein levels.

Hepatitis C virus NS5A protein interacts with 2',5'-oligoadenylate synthetase and inhibits antiviral activity of IFN in an IFN sensitivity-determining region-independent manner.

The non-structural protein 5A (NS5A) of hepatitis C virus (HCV) has been implicated in inhibition of antiviral activity of IFN. While previous studies have suggested an interaction between NS5A and the double-stranded RNA-dependent protein kinase (PKR), the possibility still remains that interaction with another molecule(s) is involved in the NS5A-mediated inhibition of IFN. In the present study, we investigated a possible interaction between NS5A and 2',5'-oligoadenylate synthetase (2-5AS), another key molecule in antiviral activity.