A brilliant disguise for self RNA: 5'-end and internal modifications of primary transcripts suppress elements of innate immunity.
RNA Biol
; 5(3): 140-4, 2008.
Article
em En
| MEDLINE
| ID: mdl-18769134
ABSTRACT
Interferon inducible protein kinase PKR is a component of innate immunity and mediates antiviral actions by recognizing pathogen associated molecular patterns (PAMPs). A well-known activator of PKR is long dsRNA, which can be produced during viral replication. Our recent results indicate that PKR can also be activated by short stem-loop RNA in a 5'-triphosphate-dependent fashion. A 5'-triphosphate is present primarily in foreign RNAs such as viral and bacterial transcripts, while a non-activating 5'-cap or 5'-monophosphate is present in most cellular RNAs. Additional studies indicate that internal RNA modifications and non-Watson-Crick motifs also repress PKR activation, and do so in an RNA structure-specific fashion. Interestingly, self-RNAs have more nucleoside modifications than non-self RNAs. Internal and 5'-end RNA modifications have repressive effects on other innate immune sensors as well, including TLR3, TLR7, TLR8, and RIG-I, suggesting that nucleoside modifications suppress innate immunity on a wide scale.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
RNA Mensageiro
/
Imunidade Inata
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article