Cloning Of UL7 Protein Of HSV-1 And Analysis Of The Expression Of UL7 Protein During The Proliferation Of HSV-1

Herpes simplex virus (HSV) is a common pathogen that is harmful to human health. HSV is divided into two serotypes:HSV-1 and HSV-2. HSV infect host through the damaged skin or mucous membrane and proliferate in epithelial tissue. On the other hand, HSV even infects neurons of nerve terminal situated in epithelial tissue. After primary infection, the virus could establish latent infection at trigeminal ganglion and dorsal root ganglion etc. The herpes simplex virus I type (herpes simplex virus I, HSV-1) can infect skin, mucous membrane and nervous system and lead to disease such as keratitis, herpes encephalitis, herpes labialis and gingivostomatitis.Tegument protein are structure protein, also acting as critical protein for virus replication. UL7 gene of HSV-1 and its encoding protein have few deep researches up to now, and corresponding literatures are rarely reported. A few studies have shown that UL7 gene among the herpes virus is highly conserved. The current studies show that as homologous gene of HSV-1 UL7, the bovine herpesvirus type 1 (BHV-1) and pseudorabies virus (PRV) UL7 mutant exhibit impaired capacity to replicate in cell culture, but the specific mechanism remains unclear. At the same time, there are some experiments show that the interaction between UL7 and UL51 of HSV-1 involved in the process of virus infection.To more systematically study the functional significance of UL7 protein in the proliferation of HSV-1, several works have been done. The UL7 gene was extracted from the genome of HSV-1 and amplified by PCR, cloned into vector of pGEX-5X-1 to construct pGEX-5X-1-UL7 for the prokaryotic expression of UL7. The plasmid was transformed into E.coli BL21(DE3) strain to express UL7 protein. GST-UL7 fusion protein was induced by IPTG and then purified. The fusion protein was used as antigen immunizing the ICR mouse to prepare the UL7-specific polyclonal antibody. The titer and specificity of the antibody were analyzed with indirect ELISA and Western blot. UL7-specific polyclonal antibody was used to detect the expression of UL7 protein at different time points after infection of Vero cell with HSV-1. Results show that GST-UL7 fusion protein was efficiently produced in E.coli BL21(DE3) strain. The indirect ELISA and Western blot results indicate that a high titer (1:163840) and specificity character of UL7-specific polyclonal antibody. The expression of UL7 protein was detected at different time points after infection of Vero cell with HSV-1. GST-UL7 fusion protein is obtained successfully and the UL7-specific polyclonal antibody is prepared. By using this polyclonal antibody for Western blot, we found a persistent expression of UL7 protein accompany with the proliferation of HSV-1.