title: Phenotypic lentivirus screens to identify functional single domain antibodies.
abstract: Manipulation of proteins is key in assessing their in vivo function. Although genetic ablation is straightforward, reversible and specific perturbation of protein function remains a challenge. Single domain antibody fragments, such as camelid-derived VHHs, can serve as inhibitors or activators of intracellular protein function, but functional testing of identified VHHs is laborious. To address this challenge, we have developed a lentiviral screening approach to identify VHHs that elicit a phenotype when expressed intracellularly. We identified 19 antiviral VHHs that protect human A549 cells from lethal infection with influenza A virus (IAV) or vesicular stomatitis virus (VSV), respectively. Both negative-sense RNA viruses are vulnerable to VHHs uniquely specific for their respective nucleoproteins. Antiviral VHHs prevented nuclear import of viral ribonucleoproteins or mRNA transcription, respectively, and may provide clues for novel antiviral reagents. In principle, the screening approach described here should be applicable to identify inhibitors of any pathogen or biological pathway.
authors: Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA.
authors: Florian I
authors: 0000-0002-9979-9769
authors: FI
authors: Schmidt
authors: Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA.
authors: Leo
authors: L
authors: Hanke
authors: Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors: Benjamin
authors: B
authors: Morin
authors: Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA.
authors: Rebeccah
authors: R
authors: Brewer
authors: Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors: Vesna
authors: V
authors: Brusic
authors: Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors: Sean P J
authors: SP
authors: Whelan
authors: Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA.|Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors: Hidde L
authors: HL
authors: Ploegh
mesh_terms: D000072283:A549 Cells; D000998:Antiviral Agents / Q000302:isolation & purification*; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D006801:Humans; D009980:Influenza A virus / Q000472:pathogenicity*; D061905:Single-Domain Antibodies / Q000302:isolation & purification*; D018116:Vesiculovirus / Q000472:pathogenicity*
chemical_list: D000998:Antiviral Agents; D061905:Single-Domain Antibodies