Combining high selectivity of replication with fiber chimerism for effective adenoviral oncolysis of CAR-negative melanoma cells.
Oncolytic adenoviruses constitute a new and promising tool for cancer treatment that has been rapidly translated into clinical trials. However, minimal or absent expression of the adenovirus serotype 5 (Ad5) receptor CAR (coxsackievirus and adenovirus receptor) on cancer cells represents a major limitation for Ad5-based oncolysis. Here, we report on the resistance of CAR-negative primary melanoma cells to cell killing by wild-type Ad5 (Ad5wt) even after high titer infection, thus underlining the need for tropism-modification of oncolytic adenoviruses. We engineered a new generation of oncolytic adenoviruses that exhibit both efficient target cell infection by swapping Ad5 fiber domains with those of Ad serotype 3, which binds to a receptor distinct from CAR, and targeted virus replication. Fiber chimerism resulted in efficient cytopathicity to primary melanoma cells, which was at least 10(4)-fold increased relative to Ad5wt. Since viral infectivity mediated by such modified viral capsids was not cell type-specific, it was pivotal to carefully restrict adenoviral replication to target cells. Towards this end, we replaced both E1A and E4 promoters of fiber chimeric viruses by tyrosinase enhancer/promoter constructs. The resulting viruses showed melanoma-specific expression of E1A and E4 and combined efficient virus replication and cell killing in melanoma cell lines and primary melanoma cells with a remarkable specificity profile that implements strong attenuation in nonmelanoma cells, including normal fibroblasts and keratinocytes.
Rivera
A A
AA
Division of Human Gene Therapy, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.
Davydova
J
J
Schierer
S
S
Wang
M
M
Krasnykh
V
V
Yamamoto
M
M
Curiel
D T
DT
Nettelbeck
D M
DM
D000256:Adenoviridae / Q000502:physiology*; D017500:Adenovirus E1A Proteins / Q000235:genetics / Q000378:metabolism; D017504:Adenovirus E4 Proteins / Q000235:genetics / Q000378:metabolism; D036022:Capsid Proteins / Q000378:metabolism; D016923:Cell Death; D046528:Chimerism; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D003588:Cytopathogenic Effect, Viral; D006801:Humans; D008545:Melanoma / Q000378:metabolism / Q000473:pathology / Q000821:virology*; D008565:Membrane Proteins / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism*; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011991:Receptors, Virus; D018523:Tropism; D014407:Tumor Cells, Cultured; D014779:Virus Replication
D017500:Adenovirus E1A Proteins; D017504:Adenovirus E4 Proteins; C568771:CLMP protein, human; D036022:Capsid Proteins; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D011991:Receptors, Virus; C018315:hexon capsid protein, Adenovirus