PLK:Δgra9 live attenuated strain induces full protective immunity against acute and chronic toxoplasmosis
会议名称：《2021中国畜牧兽医学会兽医寄生虫学分会第16次学术研讨会》
会议日期：2021年
学科分类：090603[农学-临床兽医学] 09[农学] 0906[农学-兽医学]
摘 要：Toxoplasmosis is a zoonotic parasitic disease caused by the obligate intracellular protozoa Toxoplasma gondii,which threatens a range of warm-blooded mammals including *** date,it remains a challenge to find safe and effective drug treatment or vaccine against *** this study,our results found that the development of a mutant strain based on gene disruption of dense granule protein 9(gra9) in type Ⅱ PLK strain decreased parasite replication in vivo,severely attenuated virulence in mice,and significantly reduced the formation of cysts in ***,we developed an immunization scheme to evaluate the protective immunity of the attenuated strain of Δgra9 in type Ⅱ PLK parasite as a live attenuated vaccine against toxoplasmosis in the mouse model.Δgra9 vaccination-induced full immune responses characterized by significantly high levels of pro-inflammatory cytokine interferon gamma(IFN-y) and interleukin-12(IL-12),maintained the high ***-specific IgG level,and mixed high IgG1/IgG2 a *** levels provided the complete protective immunity which is a combination of cellular and humoral immunity in mouse models against further infections of lethal doses of type Ⅰ RH,type ⅡPLK wild-type tachyzoites,or type Ⅱ PLK *** showed that Δgra9 vaccination proved its immunogenicity and potency conferring 100% protection against acute and chronic *** ***,Δgra9 vaccination provided safe and efficient immune protection against challenging parasites,suggesting that PLK:Δgra9 is a potentially promising live attenuated vaccine candidate.