The research on intracellular trafficking of adenovirus has been described mainly through observations of subgroup C adenoviruses in transformed cell lines. The basic elements of the trafficking pathway include binding to receptors at the cell surface, internalization by endocytosis, lysis of the endosomal membrane, escape to the cytosol, intracellular trafficking along microtubules, nuclear pore docking, and viral genome translocation into the nucleus. More than 80% of the adenovirus genome is delivered to the nucleus in a highly efficient manner in approximately 1 h. However, exceptions to this trafficking pattern have been noted, including: variations based on target cell type, cell physiology, and adenovirus serotype. This review summarizes mechanism of adenovirus infection pathway and intracellular trafficking, providinging a foundation for the development of clinical adenoviral vector.
Adenoviridae ; physiology ; Cell Membrane ; virology ; Cell Nucleus ; virology ; Cytoplasm ; virology ; Endocytosis ; Endosomes ; virology ; Genetic Vectors ; Humans ; Microtubules ; Virus Internalization

Biocompatible silica-overcoated magnetic nanoparticles containing an organic fluorescence dye, rhodamine B isothiocyanate (RITC), within a silica shell [50 nm size, MNP@SiO2(RITC)s] were synthesized. For future application of the MNP@SiO2(RITC)s into diverse areas of research such as drug or gene delivery, bioimaging, and biosensors, detailed information of the cellular uptake process of the nanoparticles is essential. Thus, this study was performed to elucidate the precise mechanism by which the lung cancer cells uptake the magnetic nanoparticles. Lung cells were chosen for this study because inhalation is the most likely route of exposure and lung cancer cells were also found to uptake magnetic nanoparticles rapidly in preliminary experiments. The lung cells were pretreated with different metabolic inhibitors. Our results revealed that low temperature disturbed the uptake of magnetic nanoparticles into the cells. Metabolic inhibitors also prevented the delivery of the materials into cells. Use of TEM clearly demonstrated that uptake of the nanoparticles was mediated through endosomes. Taken together, our results demonstrate that magnetic nanoparticles can be internalized into the cells through an energy-dependent endosomal-lysosomal mechanism.
Biocompatible Materials/*pharmacokinetics ; Cell Line, Tumor ; Drug Delivery Systems/methods ; Endocytosis/*physiology ; Endosomes/physiology ; Humans ; Lung Neoplasms/drug therapy/*metabolism ; Macrolides/pharmacology ; Microscopy, Confocal ; Microscopy, Electron, Transmission ; Nanoparticles/*administration & dosage ; Sodium Azide/pharmacology ; Sucrose/pharmacology ; Temperature

OBJECTIVETo observe the changes of human trophoblast cells after infected with hepatitis B virus.

METHODSHBV positive serum was used to infect human trophoblast cells in vitro. HBsAg in cell culture medium were detected by ELISA method and HBV DNA in cell culture medium and cells were detected by PCR method. HBV fluorescence polymerase chain reaction diagnose kit were used to detect the HBV DNA concentration. Ultra structure of trophoblast cells were observed with transmission electron microscopy (TEM).

RESULTSHBsAg could be detected in infection group by ELISA. Infection group cell culture medium and infection group cells were HBV DNA positive. HBV DNA concentrations in HBV infection cell culture medium in 0, 12, 36, 60, 84 h after extensively PBS washed were < 10(3), 3 x 10(4), 6 x 10(5), 5 x 10(5), 3 x 10(5) copies/mL. HBV infected trophoblast cells were found many forms of endosomes, some of which contents virus like particle.

CONCLUSIONHBV might take advantage of clathrin-mediated endocytosis to enter trophoblast cell, which might lead to cell infection or across the cell bar by transcytosis.

Animals ; Culture Media, Conditioned ; metabolism ; DNA, Viral ; analysis ; Endosomes ; virology ; Enzyme-Linked Immunosorbent Assay ; Hepatitis B Surface Antigens ; analysis ; Hepatitis B virus ; genetics ; isolation & purification ; physiology ; Humans ; Microscopy, Electron, Transmission ; Polymerase Chain Reaction ; Time Factors ; Trophoblasts ; ultrastructure ; virology