Technical Method
Construction and virulence evaluation of nonreplicative vaccinia virus modified strain NTV-C7L
Zhang Peng, Zhao Ying, Zhao Li, Ren Jiao, Tan Wenjie, Tian Houwen
Published 2020-02-29
Cite as Chinese J Exp Clin Virol, 2020,34(01): 72-77. DOI: 10.3760/cma.j.issn.1003-9279.2020.01.015
Abstract
ObjectiveTo evaluate the virulence of NTV modified strain NTV-C7L in vitro and in vivo.
MethodsThe non-replicative vaccinia virus modified strain NTV-C7L was constructed by homologous recombination, in order to evaluate the virulence of NTV-C7L by cell diffusion ability and virus replication, intranasal challenge, and scratch of tail of mice.
ResultsThe homologous recombination non-replicating vaccinia virus modified strain NTV-C7L was selected by blue-white screening, the purity of NTV-C7L was identified by PCR and Western blot, the C7L gene was successfully inserted and expressed; In human embryonic lung fibroblasts (MRC-5) as well as mouse embryonic fibroblasts (BALB/C3T3), the replication ability of NTV-C7L was recovered compared with that of NTV, but was lower than that of VTT; the result of the intranasal route with 106 PFU vaccinia virus showed that the animals infected with TTV had slightly greater weight loss than NTV or NTV-C7L(t=6.56, P<0.001; t=5.73, P<0.001). Compared with the NTV-C7L group, the weight loss of the NTV group was not statistically significant (t=0.597, P=0.081); the intranasal route with 107 PFU vaccinia virus showed that the weight loss of the NTV group and NTV-C7L group was statistically significant compared with the TTV group (t=12.86, P<0.001; t=10.71, P<0.001). Compared with the NTV-C7L group, the weight loss of the NTV group was statistically significant(t=4.616, P<0.001); the result of skin scratch indicated that mice scarified with TTV (106 PFU) formed more obvious skin redness, swelling and injury on the post infected 5 days, whereas only redness was detected after scarification with a much higher dose (107) of NTV or NTV-C7L.
ConclusionsThe intracellular and mouse virulence of NTV modified strain NTV-C7L was recovered compared with NTV, but was significantly lower than that of TTV, which provided reference for optimization and application of vaccinia virus vector.
Key words:
Non-replicating vaccinia virus modified strain NTV-C7L; Virulence; Vaccinia virus vector
Contributor Information
Zhang Peng
National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
Zhao Ying
Zhao Li
Ren Jiao
Tan Wenjie
Tian Houwen
