Abstract
Avian metapneumovirus(aMPV)is a highly contagious pathogen that causes acute upper respiratory tract diseases in chickens and turkeys,resulting in serious economic losses.Subtype B aMPV has recently become the dominant epidemic strain in China.We developed an attenuated aMPV subtype B strain by serial passaging in Vero cells and evaluated its safety and efficacy as a vaccine candidate.The safety test showed that after the 30th passage,the LN16-A strain was fully attenuated,as clinical signs of infection and histological lesions were absent after inoculation.The LN16-A strain did not revert to a virulent strain after five serial passages in chickens.The genomic sequence of LN16-A differed from that of the parent wild-type LN16(wtLN16)strain and had nine amino acid mutations.In chickens,a single immunization with LN16-A induced robust humoral and cellular immune responses,including the abundant production of neutralizing antibodies,CD4+T lymphocytes,and the Th1(IFN-y)and Th2(IL-4 and IL-6)cytokines.We also confirmed that LN16-A provided 100％protection against subtype B aMPV and significantly reduced viral shedding and turbinate inflammation.Our findings suggest that the LN16-A strain is a promising live attenuated vaccine candidate that can prevent infection with subtype B aMPV.
基金项目
国家重点研发计划(2022YFD1800604)
China Agriculture Research System(CARS-41)
Heilongjiang Touyan Innovation Team Program of China()
国家科技期刊平台
NSTL
万方数据