Prophylaxis and Treatment of Influenza A Virus Infection by Carrier-MediatedPassive Immunity

摘要

Liposome-mediated passive immunity was evaluated for its efficacy in theprophylaxis and treatment of influenza A/PR/8 virus infection in mice. A virulent, egg-propagated influenza A/PR/8 virus (H1N1) was adapted for growth in Balb/C mice. In the in vivo protection study, purified polyclonal antibody (PA) which demonstrated strong reactivity against the mouse-adapted virus in an indirect fluorogenic enzyme-linked immunosorbent assay (FELISA) and in an in vitro plaque assay, was encapsulated within liposomes. Using a radioactive tracer for the antibody molecules, the delivery of antibody to the lungs was optimized by intranasal administration of PA encapsulated within negatively charged multiamellar vesicles made from phosphatidylcholine:cholesterol:phosphatidylserine. For mice given PA intranasally 24 hours prior to challenge with 10 LD50 of mouse-adapted influenza A/PR/8 virus, the survival rate at 14 days post challenge was 60% (P < 0.05), compared to 0% for the control groups of mice given either phosphate-buffered saline (PBS) or sham liposomes.