title: Development of bioluminescence imaging of respiratory syncytial virus (RSV) in virus-infected live mice and its use for evaluation of therapeutics and vaccines.
abstract: Respiratory Syncytial virus (RSV) is one of the leading causes of pneumonia among infants with no human vaccine or efficient curative treatments. Efforts are underway to develop new RSV vaccines and therapeutics. There is a dire need for animal models for preclinical evaluation and selection of products against RSV. Herein, we developed a whole body bioluminescence imaging to follow replication of RSV A2 virus strain expressing firefly luciferase (RSVA2-line19-FFL) in live BALB/c mice that can be used as an extremely sensitive readout for studying effects of antiviral and vaccines in living mice. Strong bioluminescence signal was detected in the nasal cavity and in the lungs following intranasal infection of mice with RSVA2-line19-FFL. The kinetics of viral replication in lungs quantified by daily live imaging strongly correlated with viral titers measured by ex-vivo plaque assay and by assessing viral RNA by qRT-PCR. Vaccination of mice with a pre-fusion F protein elicited high neutralizing antibody titers conferring strong protective immunity against virus replication in the nasal cavity and lungs. In contrast, post-challenge treatment of mice with the monoclonal antibody Palivizumab two days after infection reduced viral replication in the nasal cavity at day 4, but only modestly reduced virus loads in the lungs by day 5. In contrast to RSV bioluminescence, plaque assay did not detect viral titers in lungs on day 5 in Palivizumab-treated animals. This difference between viral loads measured by the two assays was found to be due to coating of virions with the Palivizumab that blocked infection of target cells in vitro and shows importance of live imaging in evaluation of RSV therapeutics. This recombinant RSV based live imaging animal model is convenient and valuable tool that can be used to study host dissemination of RSV and evaluation of antiviral compounds and vaccines against RSV.
authors.affiliation: Division of Viral Products, Center for Biologics Evaluation and Research (CBER), FDA, Silver Spring, MD 20993, USA.
authors.forename: Sandra
authors.initials: S
authors.lastname: Fuentes
authors.affiliation: Division of Viral Products, Center for Biologics Evaluation and Research (CBER), FDA, Silver Spring, MD 20993, USA.
authors.forename: Diego
authors.initials: D
authors.lastname: Arenas
authors.affiliation: Emory Children's Center for Childhood Infections and Vaccines, Emory University School of Medicine, Emory Children's Center, Atlanta, GA 30322, USA.
authors.forename: Martin M
authors.initials: MM
authors.lastname: Moore
authors.affiliation: Division of Viral Products, Center for Biologics Evaluation and Research (CBER), FDA, Silver Spring, MD 20993, USA.
authors.forename: Hana
authors.initials: H
authors.lastname: Golding
authors.affiliation: Division of Viral Products, Center for Biologics Evaluation and Research (CBER), FDA, Silver Spring, MD 20993, USA. Electronic address: Surender.Khurana@fda.hhs.gov.
authors.forename: Surender
authors.initials: S
authors.lastname: Khurana
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000008:administration & dosage; D004195:Disease Models, Animal; D005260:Female; D017930:Genes, Reporter; D000069416:Intravital Microscopy / Q000379:methods*; D049409:Luciferases, Firefly / Q000032:analysis / Q000235:genetics; D008163:Luminescent Measurements / Q000379:methods*; D008168:Lung / Q000821:virology; D008807:Mice, Inbred BALB C; D009296:Nasal Cavity / Q000821:virology; D018357:Respiratory Syncytial Virus Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000517:prevention & control; D022261:Respiratory Syncytial Virus Vaccines / Q000008:administration & dosage; D018113:Respiratory Syncytial Virus, Human; D012136:Respiratory Syncytial Viruses / Q000302:isolation & purification*; D013194:Staining and Labeling / Q000379:methods*; D016896:Treatment Outcome; D019562:Viral Load; D051598:Whole Body Imaging / Q000379:methods*
chemical_list: D000998:Antiviral Agents; D022261:Respiratory Syncytial Virus Vaccines; D049409:Luciferases, Firefly
keywords: Animal model; Antibody; Efficacy; F protein; Immune complex; Live imaging. Ds-Cav1; Neutralization; Palivizumab; Pre-fusion F; RSV; Therapeutic; Treatment; Vaccine