A live attenuated RHΔompdcΔuprt mutant of Toxoplasma gondii induces strong protective immunity against toxoplasmosis in mice and cats  

作　　者：Yu Shen Bin Zheng Hao Sun Songrui Wu Jiyuan Fan Jianzu Ding Meng Gao Qingming Kong Di Lou Haojie Ding Xunhui Zhuo Shaohong Lu 

机构地区：[1]School of Basic Medical Sciences and Forensic Medicine,Hangzhou Medical College,Hangzhou,Zhejiang,China [2]Engineering Research Center of Novel Vaccine of Zhejiang Province,Hangzhou Medical College,Hangzhou,China [3]Key Laboratory of Bio-Tech Vaccine of Zhejiang Province,Hangzhou Medical College,Hangzhou,China

出　　处：《Infectious Diseases of Poverty》2023年第3期51-66,共16页贫困所致传染病（英文）

基　　金：supported by the National Natural Science Foundation of China(No.81871684,No.81802037);the Provincial Key R&D program of Zhejiang Department of Science and Technology(No.2019C03057);the Zhejiang Provincial Natural Science Foundation of China(No.LY22H190003);the Zhejiang Medical and Health Science and Technology Plan(WKJ-ZJ-2203);the Central Leading Local Science and Technology Development Fund Project(2023ZY1019);the Key Discipline of Zhejiang Province in Public Health and Preventive Medicine(First Class,Category A),Hangzhou Medical College.

摘　　要：Background Toxoplasma gondii is an obligate intracellular apicomplexan parasite and is responsible for zoonotic toxoplasmosis.It is essential to develop an effective anti-T.gondii vaccine for the control of toxoplasmosis,and this study is to explore the immunoprotective effects of a live attenuated vaccine in mice and cats.Methods First,theompdc anduprt genes of T.gondii were deleted through the CRISPR-Cas9 system.Then,the intracellular proliferation and virulence of this mutant strain were evaluated.Subsequently,the immune responses induced by this mutant in mice and cats were detected,including antibody titers,cytokine levels,and subsets of T lymphocytes.Finally,the immunoprotective effects were evaluated by challenge with tachyzoites of different strains in mice or cysts of the ME49 strain in cats.Furthermore,to discover the effective immune element against toxoplasmosis,passive immunizations were carried out.GraphPad Prism software was used to conduct the log-rank(Mantel–Cox)test,Student’st test and one-way ANOVA.Results The RHΔompdcΔuprt were constructed by the CRISPR-Cas9 system.Compared with the wild-type strain,the mutant notably reduced proliferation(P<0.05).In addition,the mutant exhibited virulence attenuation in both murine(BALB/c and BALB/c-nu)and cat models.Notably,limited pathological changes were found in tissues from RHΔompdcΔuprt-injected mice.Furthermore,compared with nonimmunized group,high levels of IgG(IgG1 and IgG2a)antibodies and cytokines(IFN-γ,IL-4,IL-10,IL-2 and IL-12)in mice were detected by the mutant(P<0.05).Remarkably,all RHΔompdcΔuprt-vaccinated mice survived a lethal challenge with RHΔku80 and ME49 and WH6 strains.The immunized sera and splenocytes,especially CD8^(+)T cells,could significantly extend(P<0.05)the survival time of mice challenged with the RHΔku80 strain compared with naïve mice.In addition,compared with nonimmunized cats,cats immunized with the mutant produced high levels of antibodies and cytokines(P<0.05),and notably decreased the shedding numbers of

关 键 词：Toxoplasma gondii Orotidine-5’-monophosphate decarboxylase PHOSPHORIBOSYLTRANSFERASE Live attenuated vaccine IMMUNIZATION Mouse Cat 

分 类 号：R392[医药卫生—免疫学]