Defining CAR as a cellular receptor for the avian adenovirus CELO using a genetic analysis of the two viral fibre proteins.
The coxsackievirus and adenovirus receptor (CAR) is a high affinity receptor used by adenoviruses, including adenovirus type 5 (Ad5). The adenovirus fibre molecule bears the high affinity cell binding domain of Ad5, allowing virions to attach to CAR. The avian adenovirus CELO displays two fibre molecules on its capsid and it was logical to expect that the cell binding functions of CELO might also reside in one or both of these fibres. We had previously shown that the cell binding properties of CELO resemble Ad5, suggesting that the two viruses use similar receptors. Experiments with CAR-deficient CHO cells and CHO cells modified to express CAR demonstrated that CELO has CAR-dependent transduction behaviour like Ad5. Mutations were introduced into the CELO genome to disrupt either the long fibre 1 or the short fibre 2. A CELO genome with fibre 2 disrupted did not generate virus, demonstrating that fibre 2 is essential for some stage in virus growth, assembly or spread. However, a CELO genome with disrupted fibre 1 gene produced virus (CELOdF1) that was capable of entering chicken cells, but had lost both the ability to efficiently transduce human cells and the CAR-specific transduction displayed by wild-type CELO. The ability of CELOdF1 to transduce chicken cells suggests that CELOdF1 may still bind, probably via fibre 2, to a receptor expressed on avian but not mammalian cells. CELOdF1 replication was dramatically impaired in chicken embryos, demonstrating that fibre 1 is important for the in vivo biology of CELO.
Tan
Poi Kiang
PK
Institute for Molecular Pathology, Dr Bohr-Gasse 7, A-1030 Vienna, Austria1.
Michou
Anne-Isabelle
AI
Institute for Molecular Pathology, Dr Bohr-Gasse 7, A-1030 Vienna, Austria1.
Bergelson
Jeffrey M
JM
Division of Immunologic and Infectious Diseases, Children's Hospital of Philadelphia, Philadelphia, USA2.
Cotten
Matt
M
Institute for Molecular Pathology, Dr Bohr-Gasse 7, A-1030 Vienna, Austria1.
D000818:Animals; D000259:Aviadenovirus / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D015153:Blotting, Western; D016466:CHO Cells; D002213:Capsid / Q000235:genetics / Q000378:metabolism*; D036022:Capsid Proteins; D002642:Chick Embryo; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D006224:Cricetinae; D005347:Fibroblasts; D017353:Gene Deletion; D020043:Genes, Essential / Q000235:genetics; D005814:Genes, Viral / Q000235:genetics; D022781:Hepatocytes; D006801:Humans; D051379:Mice; D011991:Receptors, Virus / Q000235:genetics / Q000378:metabolism*; D013045:Species Specificity; D013379:Substrate Specificity; D014161:Transduction, Genetic; D014407:Tumor Cells, Cultured; D019065:Virus Assembly; D014779:Virus Replication
C568771:CLMP protein, human; C568772:CLMP protein, mouse; D036022:Capsid Proteins; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D011991:Receptors, Virus; C018315:hexon capsid protein, Adenovirus