Expression Of Newcastle Disease Virus V Protein And Its Effect On Interferon

Newcastle disease virus (NDV) causes a highly contagious respiratory, neurological, or enteric disease in chickens. Because of server economic losses caused by NDV, the pathogenisis and immune mechanism is the main investigation field. The interferon (IFN) system is the first line of host defense against virus infection. Recent studies show that V protein of many paramyxoviruses are responsible for blocking the antiviral action of IFN. AS an avian paramyxovirus, NDV is a member of genus Avulavirus in the family Paramyxoviridae, its genome consists of six genes that encode six proteins, NP, P, M, F, HN and L. Two additional proteins, V and W, are expressed by mRNAs, which are derived from the P gene via RNA editing. The V protein of NDV, in common with its counterparts in other paramyxoviruses, is cysteine rich within its unique carboxyl-terminal region and binds to zinc. Because of the special similar structures, NDV V protein probably plays an important role in antagonizing the host's innate response and viral pathogenicity. To understand the function of NDV V protein, the prokaryotic and eukaryotic expression systems expressing NDV V protein were constructed, and used in studying of V protein in cells or chickens.The partial cDNA (contain full length of V gene) of chicken, pigeon and goose NDV P protein genes were amplified from allantoic fluid of chicken embryo by reveres transcription- polymerase chain reaction (RT-PCR). Then it was cloned into pMD18-T vector and named as pMD18-T-c-P,pMD18-T-p-P and pMD18-T-g-P. Recombinants with cDNA were used as template to amplify the V gene. The primer V1 and V2 was used to introduce a necessary mutation for the expression of V protein, the mutagenic partial segment V12 of V gene was got by PCR and used as primer in the second PCR. The full length cDNA of NDV V gene was got by using the V12 and V3 and cloned...