Herpes simplex virus-1 induces expression of a novel MxA isoform that enhances viral replication
Journal
Immunology and cell biology
Journal Volume
89
Journal Issue
2
Pages
173
Date Issued
2011-02
Author(s)
Che, Xi-Bing
Reichelt, Mike
Rajamani, Jaya
Schaap-Nutt, Anne
Huang, Ke-Jung
Sommer, Marvin H
Chen, Yi-Shun
Chen, Yi-Yuan
Arvin, Ann M
Abstract
MxA is an antiviral protein induced by interferon (IFN)-α/β that is known to inhibit the replication of many RNA viruses. In these experiments, the 76-kDa MxA protein expressed in IFN-α-treated cells was shown to have antiviral activity against herpes simplex virus-1 (HSV-1), a human DNA virus. However, MxA was expressed as a 56-kDa protein in HSV-1-infected cells in the absence of IFN-α. This previously unrecognized MxA isoform was produced from an alternatively spliced MxA transcript that had a deletion of Exons 14-16 and a frame shift altering the C-terminus. The variant MxA (varMxA) isoform was associated with HSV-1 regulatory proteins and virions in nuclear replication compartments. varMxA expression enhanced HSV-1 infection as shown by a reduction in infectious virus titers from cells in which MxA had been inhibited by RNA interference and by an increase in HSV-1 titers when the 56-kDa varMxA was expressed constitutively. Thus, the human MxA gene encodes two MxA isoforms, which are expressed differentially depending on whether the stimulus is IFN-α or HSV-1. These findings show that alternative splicing of cellular mRNA can result in expression of a novel isoform of a host defense gene that supports instead of restricting viral infection.
Subjects
herpes simplex virus-1 | IFN-α/β | immune evasion | mRNA alternative splicing
SDGs
Publisher
WILEY
Type
journal article