ABSTRACT
OBJECTIVES: Our aim was to investigate the effect of PEGylation on the uptake of osteoprotegerin/osteoclastogenesis inhibitory factor (OPG/OCIF) into rat liver, kidney and spleen, and human liver. METHODS: Copolymer of polyethyleneglycol allylmethylether and maleamic acid sodium salt with OCIF (poly(PEG)-OCIF) (0.5 mg/kg) was administered to rats and the concentrations of poly(PEG)-OCIF in the liver, kidney and spleen at 15 min after administration were measured by ELISA. For human liver uptake, the liver perfusion of OCIF and (3)H-labelled poly(PEG)-OCIF was conducted using fresh human liver block. KEY FINDINGS: The tissue uptake of poly(PEG)-OCIF in rats was significantly lower compared with that of OCIF. In fresh human liver perfusion, (3)H-poly(PEG)-OCIF was rarely taken up into the liver. On the other hand, more than 50% of the perfused OCIF was taken up. CONCLUSIONS: PEGylation of OCIF using poly(PEG) dramatically suppressed the uptake of OCIF into human liver as well as into rat liver and could be a promising approach for improving the pharmacokinetic and pharmacological effects of OCIF in the clinical setting.
Subject(s)
Bone Density Conservation Agents/pharmacokinetics , Liver/metabolism , Osteoprotegerin/pharmacokinetics , Polyethylene Glycols/chemistry , Animals , Biological Transport , Bone Density Conservation Agents/administration & dosage , Bone Density Conservation Agents/blood , Bone Density Conservation Agents/chemistry , Cells, Cultured , Chemistry, Pharmaceutical , Down-Regulation , Enzyme-Linked Immunosorbent Assay , Female , Heparin/metabolism , Humans , Injections, Intravenous , Kidney/metabolism , Maleates/chemistry , Mice , Osteoclasts/drug effects , Osteoprotegerin/administration & dosage , Osteoprotegerin/blood , Osteoprotegerin/chemistry , Ovariectomy , Perfusion , Rats , Rats, Sprague-Dawley , Spleen/metabolism , Tissue DistributionABSTRACT
To assess whether the antigenic properties of H5 hemagglutinin (HA) change over time due to antigenic drift, we produced a panel of monoclonal antibodies (mAbs) against the HA of the index H5N1 human influenza A virus, A/Hong Kong/156/97. By immunizing mice with a plasmid expressing this HA and boosting the initial immunization with cell lysates transfected with the plasmid, a total of six hybridomas producing HA-specific mAbs were established: four to the HA1 subunit with hemadsorption-inhibiting activity and two to the HA2 subunit. None of the mAbs to HA1 could bind to the HA of a recent human isolate, A/Hong Kong/213/2003, indicating that there are substantial antigenic differences between the H5N1 human influenza virus isolated in 1997 and that isolated in 2003.
