RESUMO
The fate of plasmid DNA complexed with cationic lipids delivered intravenously in mice was evaluated at selected timepoints up to 6 months postinjection. Blood half-life and tissue distribution of plasmid DNA and potential expression in tissues were examined. Southern blot analyses of blood indicated that intact plasmid DNA was rapidly degraded, with a half-life of less than 5 min for intact plasmid, and was no longer detectable at 1 hr postinjection. Southern analyses of tissue demonstrated that intact DNA was differentially retained in the lung, spleen, liver, heart, kidney, marrow, and muscle up to 24 hr postinjection. After 7 days, no intact plasmid DNA was detectable by Southern blot analysis; however, the plasmid was detectable by the polymerase chain reaction (PCR) in all tissues examined at 7 and 28 days postinjection. At 6 months postinjection, femtogram levels of plasmid were detected only in muscle. Immunohistochemical analyses did not detect encoded protein in the tissues harboring residual plasmid at 1 or 7 days postinjection.
Assuntos
DNA , Terapia Genética , Antígeno HLA-B7/genética , Lipídeos/farmacocinética , Neoplasias/terapia , Plasmídeos/farmacocinética , Animais , Sequência de Bases , Cátions/química , Células Cultivadas , DNA Recombinante , Feminino , Genes MHC Classe I , Humanos , Imuno-Histoquímica , Injeções Intravenosas , Lipídeos/administração & dosagem , Lipídeos/sangue , Lipídeos/química , Lipídeos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Dados de Sequência Molecular , Plasmídeos/administração & dosagem , Plasmídeos/sangue , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas , Distribuição Tecidual , Transfecção , Células Tumorais Cultivadas , Microglobulina beta-2/genéticaRESUMO
Antibodies to the influenza virus nucleoprotein are produced after injection of a plasmid DNA expression vector containing the nucleoprotein gene. A single injection of 10 to 100 micrograms of DNA produces IgG antibodies which first appear four to six weeks post injection. Antibody titres peak at six to eight weeks and then remain stable in most animals for many months. The antibody response at early times is dose-dependent, with higher amounts of DNA producing a faster immune response as well as higher antibody titres. Titres observed many months after injection are less dependent on DNA dose.
