SR-N-SH در يك كشت سلولي با منشاء عصبي بنام ICP43.5 بررسي جلوگيري از توقف سنتز پروتيين و مرگ سلول ميزبان بوسيله يك ژن هرپس سيمپلكس ويروس نوع يك بنام

Investigation of host cell protein synthesis shut-off inhibition by a Herpes simplex virus type-1 gene,ICP34.5, in a neuronal cell line, SK-N-SH

Background and aim: The cellular response to virus infection is a complex process and includes induction of interferons (IFNs). IFNs are key components of the host innate immunity to virus infection and act through several pathways to block virus growth and virulence. Cells infected with a variety of viruses synthesize double stranded RNA, which induces an IFN response. Protein kinase R (PKR) is induced by IFNs and is a major mediator of the cellular response to virus infection. PKR becomes activated and phosphorylates initiation factor-2Alpha (eIF-2Alpha). This leads to the loss of functional elF-2a, which results in inhibition of protein synthesis. In herpes simplex virus type-l (HSV-1) infected cells, activation of the PKR pathway results in premature shut-off of host protein synthesis. However, MT -I encodes a gene, ICP34.5, which blocks the shut-off of the host protein synthesis. This gene is the virulence factor of this virus in the central nervous system of the mice. This gene is not essential for replication of this virus in some cell lines. However, its role in neuronal cell lines such as SK-N-SH cells following infection with recombinant mutant expressing ICP34.5 specifically, has not been investigated. The aim of this research was to investigate this role. Method: Based on homologous recombination, a number of MY -I recombinants constructed, their DNA analyzed by using Southern blotting and they were characterized by using Western blotting and host shut-off techniques. Following infection of SK-N-SH cells, inhibition of host protein synthesis shut-off by this mutant compared with a deletion mutant lacking this gene and an HSV -l wild type has been investigated. Results: the results showed that ICP34.5 is essential for maintenance of host protein synthesis and thus replication of HSV-I in this cell line. Conclusion: In cells infected with HSV 1, the function of this gene is the inhibition of host protein synthesis shut-off, induced by infected cell.