{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,15]],"date-time":"2026-02-15T14:41:47Z","timestamp":1771166507086,"version":"3.50.1"},"reference-count":40,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2020,1,6]],"date-time":"2020-01-06T00:00:00Z","timestamp":1578268800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Toxoplasma gondii is a protozoan parasite, occurring worldwide, endangers human health and causes enormous economic losses to the Ministry of Agriculture. A safe and effective vaccination is needed to handle these problems. In addition, ideal vaccine production is a challenge in the future. In this study, we knocked out the adenylosuccinate lyase (ADSL) gene and found that the gene reduces the growth rate of T. gondii tachyzoites in vitro under standard growth conditions by plaque or replication experiments. Furthermore, mice that were immunized with tachyzoites of the ME49\u0394ADSL strain induced 100% protection efficacy against challenge with the type 1 strain RH, type 2 strain ME49 and type 3 strain VEG. All mice that were immunized with ME49\u0394ADSL had a survival rate of 100% when they were reinfected with wild-type strains, either 30 days or 70 days after immunization, and immunization was also protective against homologous infection with 50 T. gondii ME49 tissue cysts. In addition, the level of Toxoplasma-specific IgG was significantly elevated at 30 and 70 days after immunization. ME49\u0394ADSL induced high levels of Th1 cytokines (interferon gamma (IFN-\u03b3), interleukin (IL)-12) at 4 weeks after immunization and spleen cell cultures from mice vaccinated for 150 days were able to produce robust INF-\u03b3 and IL-12 levels in the supernatant. The results of the present study showed that \u0394ADSL vaccination induced a T. gondii-specific cellular immune response against further infections. These results suggest that the ADSL-deficient vaccine can induce anti-Toxoplasma gondii humoral and cellular immune responses and has 100% immune protection against post-challenge by the type 1 strain RH, type 2 strain ME49 and type 3 strain VEG. It will be used as an excellent candidate for live vaccines and may contribute in a positive meaning to control human toxoplasmosis.<\/jats:p>","DOI":"10.3390\/vaccines8010016","type":"journal-article","created":{"date-parts":[[2020,1,6]],"date-time":"2020-01-06T10:34:46Z","timestamp":1578306886000},"page":"16","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Toxoplasma gondii ADSL Knockout Provides Excellent Immune Protection against a Variety of Strains"],"prefix":"10.3390","volume":"8","author":[{"given":"Luyao","family":"Wang","sequence":"first","affiliation":[{"name":"State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ding","family":"Tang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chenghang","family":"Yang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jing","family":"Yang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rui","family":"Fang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,1,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1111\/j.1550-7408.2008.00345.x","article-title":"The history of Toxoplasma gondii\u2014The first 100 years","volume":"55","author":"Dubey","year":"2008","journal-title":"J. Eukaryot. Microbiol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"781","DOI":"10.1016\/S0140-6736(83)91847-0","article-title":"Outbreak of central-nervous-system toxoplasmosis in western Europe and North America","volume":"1","author":"Luft","year":"1983","journal-title":"Lancet"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1965","DOI":"10.1016\/S0140-6736(04)16412-X","article-title":"Toxoplasmosis","volume":"363","author":"Montoya","year":"2004","journal-title":"Lancet"},{"key":"ref_4","first-page":"211","article-title":"Toxoplasmosis in the adult","volume":"50","author":"Remington","year":"1974","journal-title":"Bull. N. Y. Acad. Med."},{"key":"ref_5","first-page":"249","article-title":"Toxoplasmosis and pregnancy. Evaluation of 2 years of prevention of congenital toxoplasmosis in the maternity ward of Hopital Saint-Antoine (1973-1974)","volume":"5","author":"Roux","year":"1976","journal-title":"J. Gynecol. Obstet. Biol. Reprod. (Paris)"},{"key":"ref_6","first-page":"155","article-title":"Epizootiologic investigations on a sheep farm with Toxoplasma gondii-induced abortions","volume":"188","author":"Dubey","year":"1986","journal-title":"J. Am. Vet. Med. Assoc."},{"key":"ref_7","first-page":"697","article-title":"Toxoplasma gondii-induced abortion in sheep","volume":"193","author":"Dubey","year":"1988","journal-title":"J. Am. Vet. Med. Assoc."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"273","DOI":"10.2147\/DDDT.S60973","article-title":"Drugs in development for toxoplasmosis: Advances, challenges, and current status","volume":"11","author":"Alday","year":"2017","journal-title":"Drug Des. Dev. Ther."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"S11","DOI":"10.1017\/S003118200000144X","article-title":"A commercial vaccine for ovine toxoplasmosis","volume":"110","author":"Buxton","year":"1995","journal-title":"Parasitology"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1080\/00480169.1983.35017","article-title":"Effect on lambing percentage of vaccinating ewes with Toxoplasma gondii","volume":"31","author":"Wilkins","year":"1983","journal-title":"N. Z. Vet. J."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/S0304-4017(03)00044-X","article-title":"Immune responses against excreted\/secreted antigens of Toxoplasma gondii tachyzoites in the murine model","volume":"113","author":"Daryani","year":"2003","journal-title":"Vet. Parasitol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"60","DOI":"10.2307\/3281275","article-title":"Live and killed vaccines against toxoplasmosis in mice","volume":"69","author":"Waldeland","year":"1983","journal-title":"J. Parasitol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"6757","DOI":"10.1016\/j.vaccine.2015.10.077","article-title":"Toxoplasma gondii: Vaccination with a DNA vaccine encoding T- and B-cell epitopes of SAG1, GRA2, GRA7 and ROP16 elicits protection against acute toxoplasmosis in mice","volume":"33","author":"Cao","year":"2015","journal-title":"Vaccine"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1016\/j.exppara.2007.01.017","article-title":"Toxoplasma gondii: DNA vaccination with genes encoding antigens MIC2, M2AP, AMA1 and BAG1 and evaluation of their immunogenic potential","volume":"116","author":"Dautu","year":"2007","journal-title":"Exp. Parasitol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1007\/s00436-003-0992-5","article-title":"Protective immunity against Toxoplasma gondii in mice induced by a chimeric protein rSAG1\/2","volume":"92","author":"Yang","year":"2004","journal-title":"Parasitol. Res."},{"key":"ref_16","first-page":"59","article-title":"Toxoplasma gondii-Derived Synthetic Peptides Containing B- and T-Cell Epitopes from GRA2 Protein Are Able to Enhance Mice Survival in a Model of Experimental Toxoplasmosis","volume":"6","author":"Bastos","year":"2016","journal-title":"Front. Cell. Infect. Microbial."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"174","DOI":"10.5455\/javar.2019.f329","article-title":"Epitope-based vaccine as a universal vaccination strategy against Toxoplasma gondii infection: A mini-review","volume":"6","author":"Hajissa","year":"2019","journal-title":"J. Adv. Vet. Anim. Res."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"4","DOI":"10.7774\/cevr.2019.8.1.4","article-title":"Rhoptry antigens as Toxoplasma gondii vaccine target","volume":"8","author":"Foroutan","year":"2019","journal-title":"Clin. Exp. Vaccine Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"5380","DOI":"10.1128\/IAI.00649-09","article-title":"Long-term immunity to lethal acute or chronic type II Toxoplasma gondii infection is effectively induced in genetically susceptible C57BL\/6 mice by immunization with an attenuated type I vaccine strain","volume":"77","author":"Gigley","year":"2009","journal-title":"Infect. Immun."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"730","DOI":"10.3389\/fimmu.2017.00730","article-title":"Immunization with Toxoplasma gondii GRA17 Deletion Mutant Induces Partial Protection and Survival in Challenged Mice","volume":"8","author":"Wang","year":"2017","journal-title":"Front. Immunol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"768","DOI":"10.1093\/infdis\/jiy211","article-title":"Live Attenuated Pru: Deltacdpk2 Strain of Toxoplasma gondii Protects against Acute, Chronic, and Congenital Toxoplasmosis","volume":"218","author":"Wang","year":"2018","journal-title":"J. Infect. Dis."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1814","DOI":"10.3389\/fimmu.2018.01814","article-title":"A Lactate Fermentation Mutant of Toxoplasma Stimulates Protective Immunity Against Acute and Chronic Toxoplasmosis","volume":"9","author":"Xia","year":"2018","journal-title":"Front. Immunol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"10601","DOI":"10.1016\/S0021-9258(18)81663-5","article-title":"Purine metabolism in Toxoplasma gondii","volume":"264","author":"Krug","year":"1989","journal-title":"J. Biol. Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"470","DOI":"10.1111\/j.1550-7408.1971.tb03356.x","article-title":"Incorporation of precursors into Toxoplasma DNA","volume":"18","author":"Perrotto","year":"1971","journal-title":"J. Protozool."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"31221","DOI":"10.1074\/jbc.M404232200","article-title":"Purine salvage pathways in the apicomplexan parasite Toxoplasma gondii","volume":"279","author":"Chaudhary","year":"2004","journal-title":"J. Biol. Chem."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1016\/S0091-679X(08)61845-2","article-title":"Molecular tools for genetic dissection of the protozoan parasite Toxoplasma gondii","volume":"45","author":"Roos","year":"1994","journal-title":"Methods Cell Biol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1007\/978-1-4939-6472-7_6","article-title":"Development of CRISPR\/Cas9 for Efficient Genome Editing in Toxoplasma gondii","volume":"1498","author":"Shen","year":"2017","journal-title":"Methods Mol. Biol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"e01114","DOI":"10.1128\/mBio.01114-14","article-title":"Efficient gene disruption in diverse strains of Toxoplasma gondii using CRISPR\/CAS9","volume":"5","author":"Shen","year":"2014","journal-title":"MBio"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1007\/s12639-016-0794-1","article-title":"Evaluation of Toxoplasma gondii soluble, whole and excretory\/secretary antigens for diagnosis of toxoplasmosis by ELISA test","volume":"41","author":"Pishkari","year":"2017","journal-title":"J. Parasit. Dis."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Melzer, T.C., Cranston, H.J., Weiss, L.M., and Halonen, S.K. (2010). Host Cell Preference of Toxoplasma gondii Cysts in Murine Brain: A Confocal Study. J. Neuroparasitol., 1.","DOI":"10.4303\/jnp\/N100505"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Xia, N., Yang, J., Ye, S., Zhang, L., Zhou, Y., Zhao, J., David Sibley, L., and Shen, B. (2018). Functional analysis of Toxoplasma lactate dehydrogenases suggests critical roles of lactate fermentation for parasite growth in vivo. Cell. Microbiol., 20.","DOI":"10.1111\/cmi.12794"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"3584","DOI":"10.4049\/jimmunol.141.10.3584","article-title":"Molecular analysis of the gene encoding the major surface antigen of Toxoplasma gondii","volume":"141","author":"Burg","year":"1988","journal-title":"J. Immunol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1111\/j.1365-3024.1987.tb00521.x","article-title":"Isolation and characterization of a monoclonal anti-P30 antibody resistant mutant of Toxoplasma gondii","volume":"9","author":"Kasper","year":"1987","journal-title":"Parasite Immunol."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Saraav, I., Wang, Q., Brown, K.M., and Sibley, L.D. (2019). Secretory Microneme Proteins Induce T-Cell Recall Responses in Mice Chronically Infected with Toxoplasma gondii. mSphere, 4.","DOI":"10.1128\/mSphere.00711-18"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"3090","DOI":"10.1128\/IAI.01722-14","article-title":"Complex immune cell interplay in the gamma interferon response during Toxoplasma gondii infection","volume":"82","author":"Sturge","year":"2014","journal-title":"Infect. Immun."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"516","DOI":"10.1126\/science.3128869","article-title":"Interferon-gamma: The major mediator of resistance against Toxoplasma gondii","volume":"240","author":"Suzuki","year":"1988","journal-title":"Science"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1016\/0014-4894(82)90094-7","article-title":"Toxoplasma gondii: Purine synthesis and salvage in mutant host cells and parasites","volume":"53","author":"Schwartzman","year":"1982","journal-title":"Exp. Parasitol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1038\/nri3598","article-title":"Innate immunity to Toxoplasma gondii infection","volume":"14","author":"Yarovinsky","year":"2014","journal-title":"Nat. Rev. Immunol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"766","DOI":"10.1038\/nrmicro2858","article-title":"Modulation of innate immunity by Toxoplasma gondii virulence effectors","volume":"10","author":"Hunter","year":"2012","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"798","DOI":"10.4049\/jimmunol.157.2.798","article-title":"In the absence of endogenous IL-10, mice acutely infected with Toxoplasma gondii succumb to a lethal immune response dependent on CD4 + T cells and accompanied by overproduction of IL-12, IFN-gamma and TNF-alpha","volume":"157","author":"Gazzinelli","year":"1996","journal-title":"J. Immunol."}],"container-title":["Vaccines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-393X\/8\/1\/16\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,13]],"date-time":"2025-10-13T13:28:53Z","timestamp":1760362133000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-393X\/8\/1\/16"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,1,6]]},"references-count":40,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2020,3]]}},"alternative-id":["vaccines8010016"],"URL":"https:\/\/doi.org\/10.3390\/vaccines8010016","relation":{},"ISSN":["2076-393X"],"issn-type":[{"value":"2076-393X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,1,6]]}}}