Studies On Protein Transduction Of VP22 In CVI988 Attenuated Vaccine Strain Of Marek's Disease Virus

The UL49 homolog (UL49h) gene of Marek's disease virus serotype 1 (MDV-1) encodes the viral protein 22 (VP22) of 27.6kD with a homology of about 25% to the VP22 of Herpes Simplex virus type 1 (HSV-1). In HSV-1, VP22 is a novel translocating protein with a potential protein tranduction domain (PTD) in its cytoplamic region, which has been successfully used to enhance the delivery and therapeutic or immuno-stimulatory effects of several proteins in vitro or in vivo. The VP22 protein in the virulent MDV-1 strain RB1B has an intercellular trafficking function similar to that of HSV-1, which appears to be indispensable for cell-to-cell spread and propagation of MDV-1. A DNA vaccine containing the E7 gene of human papillomavirus type 16 linked to MDV-1 VP22 gene has a significantly increased immunogenicity in terms of stimulating E7-Specific CD8+ T cells, suggesting that the MDV-1 VP22 is an alternative transduction protein for enhancing vaccine potency.Our previous data showed that the VP22 of the attenuated MDV-1 strain CVI988/Rispens had a deletion of 201TKSERT206 compared to that of the oncogenic GA strain and other virulent strains. To investigate the influence of the deletion on the intercellular trafficking of the VP22 protein, antibodies specific for the carboxyl terminus of CVI988 VP22 was prepared by immunizing mice with truncated protein expressed in E. coli, and used to detect the expression and functions of VP22 and its truncated proteins/peptides in different eukocytic systems. It was described that the preliminary applications of VP22 in avirulent vaccine strain CVI988/Rispens and in the strategies for novel vaccines.The sequence comparison of VP22 protein amplified from different pathotypes of Marek's disease virusSeveral fragments of VP22 gene were amplified from total DNAs, which were extracted...