A transgenic ginseng vaccine for bovine viral diarrhea.

Yugang Gao,Pu Zang,Lianxue Zhang,He Yang,Xueliang Zhao,Chao Sun,Ran Li

doi:10.1186/s12985-015-0301-9

Abstract

BackgroundBovine viral diarrhea virus (BVDV) infections are endemic in cattle populations worldwide and cause major economic losses. Thus, an effective vaccine is needed against the transmission of BVDV. The glycoprotein Erns is one of the envelope proteins of this virus and shows BVDV-related immunogenicity. Here, we report the use of Panax ginseng as an alternative production platform for the expression of glycoprotein Erns via Agrobacterium-mediated transformation.ResultPolymerase chain reaction (PCR) and reverse transcription (RT)-PCR analyses showed that pBI121-Erns was stably integrated into the chromosome of transformants. ELISA assay and Western blot analysis confirmed the antigenicity of plant-derived Erns glycoprotein. Immunogenicity was evaluated subcutaneously in deer using a soluble protein extract of dried transgenic ginseng hairy roots. Specific humoral and cell-mediated immune responses against BVDV were detected following immunization.ConclusionThese results demonstrated that the Erns glycoprotein could be expressed in ginseng hairy roots and that plant-derived glycoprotein Erns retained its antigenicity and immunogenicity.

Highlights

Bovine viral diarrhea virus (BVDV) is a positive-stranded RNA virus of the Flaviviridae family [1,2] and an important cause of economic loss in herds worldwide
After the isolation of genomic DNA and total RNA from transgenic hairy roots, 706 bp long bands were detected using polymerase chain reaction (PCR) and reverse transcription (RT)-Polymerase chain reaction (PCR) in all ginseng hairy roots except in the negative control groups, which confirmed the stable integration of the expression vector pBI121-Erns into the chromosome of the transformants (Figure 1A and B)
The result showed that the soluble proteins from the transgenic group had immune reactivity against anti-BVDV antiserum and the OD490 values of the transgenic groups were significantly higher than those of the negative controls (Figure 2A), which implied that Erns protein was expressed and accumulated in transgenic Panax ginseng

Summary

Introduction

Bovine viral diarrhea virus (BVDV) is a positive-stranded RNA virus of the Flaviviridae family [1,2] and an important cause of economic loss in herds worldwide. BVDV Erns expressed in prokaryotic systems produces neutralizing antibodies; they are produced at low titers that are unable to efficiently neutralize the virus. This was attributed to the misfolding of Erns when expressed in prokaryotes [23]. Truncated glycoprotein BVDV E2 has been expressed in Nicotiana tabacum leaves and subsequently showed high reactivity in virus neutralization tests [28]. Another way to improve the immune activity of vaccines is the use of an adjuvant. Research has shown that extracts of ginseng can exert a number of effects on the immune system such as improvement of the phagocytic activity of macrophages, lymphocyte proliferation enhancement, cytokine production stimulation, and increased activity of neutrophils, CD4+ T cells, and natural killer cells [32,33,34]

Results

Discussion

Materials and methods

Conclusions