Lentivirus vectors pseudotyped with filoviral envelope glycoproteins transduce airway epithelia from the apical surface independently of folate receptor alpha.
The practical application of gene therapy as a treatment for cystic fibrosis is limited by poor gene transfer efficiency with vectors applied to the apical surface of airway epithelia. Recently, folate receptor alpha (FR alpha), a glycosylphosphatidylinositol-linked surface protein, was reported to be a cellular receptor for the filoviruses. We found that polarized human airway epithelia expressed abundant FR alpha on their apical surface. In an attempt to target these apical receptors, we pseudotyped feline immunodeficiency virus (FIV)-based vectors by using envelope glycoproteins (GPs) from the filoviruses Marburg virus and Ebola virus. Importantly, primary cultures of well-differentiated human airway epithelia were transduced when filovirus GP-pseudotyped FIV was applied to the apical surface. Furthermore, by deleting a heavily O-glycosylated extracellular domain of the Ebola GP, we improved the titer of concentrated vector severalfold. To investigate the folate receptor dependence of gene transfer with the filovirus pseudotypes, we compared gene transfer efficiency in immortalized airway epithelium cell lines and primary cultures. By utilizing phosphatidylinositol-specific phospholipase C (PI-PLC) treatment and FR alpha-blocking antibodies, we demonstrated FR alpha-dependent and -independent entry by filovirus glycoprotein-pseudotyped FIV-based vectors in airway epithelia. Of particular interest, entry independent of FR alpha was observed in primary cultures of human airway epithelia. Understanding viral vector binding and entry pathways is fundamental for developing cystic fibrosis gene therapy applications.
Sinn
Patrick L
PL
Program in Gene Therapy, Department of Pediatrics, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA.
Hickey
Melissa A
MA
Staber
Patrick D
PD
Dylla
Douglas E
DE
Jeffers
Scott A
SA
Davidson
Beverly L
BL
Sanders
David A
DA
McCray
Paul B
PB
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002415:Cats; D016764:Cell Polarity; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000821:virology; D016563:Filoviridae / Q000235:genetics / Q000378:metabolism*; D058973:Folate Receptors, GPI-Anchored; D005822:Genetic Vectors; D006801:Humans; D016089:Immunodeficiency Virus, Feline / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D011956:Receptors, Cell Surface; D012137:Respiratory System / Q000166:cytology / Q000821:virology*; D014161:Transduction, Genetic; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism*
D002352:Carrier Proteins; D058973:Folate Receptors, GPI-Anchored; D011956:Receptors, Cell Surface; D014759:Viral Envelope Proteins