Herpes simplex virus‐1 induces expression of a novel MxA isoform that enhances viral replication

Autor: Chia-Chi Ku, Yi-Yuan Chen, Marvin Sommer, Anne Schaap-Nutt, Mike Reichelt, Ke-Jung Huang, Ann M. Arvin, Xibing Che, Yi-Shun Chen, Jaya Rajamani
Rok vydání: 2010
Předmět:
Zdroj: Immunology & Cell Biology. 89:173-182
ISSN: 1440-1711
0818-9641
Popis: 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.
Databáze: OpenAIRE
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